Class: MilkTea::SemanticAnalyzer::Checker

Inherits:
Object
  • Object
show all
Includes:
CompatibilityHelpers
Defined in:
lib/milk_tea/core/semantic_analyzer.rb,
lib/milk_tea/core/semantic_analyzer/calls.rb,
lib/milk_tea/core/semantic_analyzer/generics.rb,
lib/milk_tea/core/semantic_analyzer/top_level.rb,
lib/milk_tea/core/semantic_analyzer/attributes.rb,
lib/milk_tea/core/semantic_analyzer/statements.rb,
lib/milk_tea/core/semantic_analyzer/expressions.rb,
lib/milk_tea/core/semantic_analyzer/nullability.rb,
lib/milk_tea/core/semantic_analyzer/flow_refinement.rb,
lib/milk_tea/core/semantic_analyzer/name_resolution.rb,
lib/milk_tea/core/semantic_analyzer/analysis_context.rb,
lib/milk_tea/core/semantic_analyzer/function_binding.rb,
lib/milk_tea/core/semantic_analyzer/type_declaration.rb,
lib/milk_tea/core/semantic_analyzer/foreign_functions.rb,
lib/milk_tea/core/semantic_analyzer/type_compatibility.rb,
lib/milk_tea/core/semantic_analyzer/interface_conformance.rb

Constant Summary collapse

INTEGER_SUFFIX_TYPES = 
{
  "ub" => "ubyte",
  "b" => "byte",
  "us" => "ushort",
  "s" => "short",
  "u" => "uint",
  "i" => "int",
  "ul" => "ulong",
  "l" => "long",
  "z" => "ptr_uint",
  "iz" => "ptr_int",
}.freeze
BUILTIN_CALLABLE_NAMES =

Names recognised as builtin callable / type-constructor identifiers by resolve_callable and the compile-time evaluation path. We allow these so the generic-name check does not flag them as unknown before the full type checker has a chance to handle the surrounding Specialization / Call context.

%w[
  fatal ref_of const_ptr_of read ptr_of
  field_of fields_of callable_of attribute_of has_attribute
  members_of attributes_of get
  reinterpret array span zero default hash equal order
  adapt attribute_arg
  Task Option Result SoA str_buffer atomic
].to_set.freeze
PRELUDE_MODULE_PATHS = 
%w[std.option std.result].freeze
PRELUDE_TYPE_DEFINING_MODULES = 
{
  "Option" => "std.option",
  "Result" => "std.result",
}.freeze

Constants included from CompatibilityHelpers

CompatibilityHelpers::ATOMIC_METHOD_KINDS, CompatibilityHelpers::BUILTIN_CSTR, CompatibilityHelpers::EVENT_METHOD_KINDS, CompatibilityHelpers::EVENT_METHOD_NAMES, CompatibilityHelpers::SIMD_METHOD_KINDS, CompatibilityHelpers::STR_BUFFER_METHOD_KINDS, CompatibilityHelpers::STR_BUFFER_METHOD_NAMES

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from CompatibilityHelpers

#event_subscription_result_type, #event_wait_result_type, #range_expr?, #string_literal_cstr_compatibility?, #type_ref_from_specialization

Methods included from Types::Predicates

#arity_error_message, #call_arity_matches?, #callable_param_ref_supported?, #char_pointer_type?, #char_type?, #const_pointer_to, #const_pointer_type?, #contains_ref_type?, #contextual_int_to_float_compatibility?, #contextual_int_to_float_target?, #dyn_type?, #exact_integer_constant_value, #exactly_representable_float32?, #external_numeric_compatibility?, #external_typed_null_pointer_compatibility?, #flatten_field_types, #float_constant_fits_type?, #foreign_boundary_element_compatible?, #foreign_char_pointer_buffer_boundary_compatible?, #foreign_external_layout_compatible?, #foreign_external_layout_field_compatible?, #foreign_function_type_projection_compatible?, #foreign_identity_projection_cast_compatible?, #foreign_identity_projection_compatible?, #foreign_identity_projection_reinterpret_compatible?, #foreign_opaque_c_name, #foreign_span_boundary_compatible?, #function_type_matches_proc_type?, #integer_constant_fits_type?, #integer_like_char_source_type?, #integer_to_char_compatibility?, #lossless_external_integer_compatibility?, #lossless_integer_compatibility?, #method_dispatch_receiver_type, #mutable_pointer_type?, #mutable_to_const_pointer_compatibility?, #native_foreign_layout_compatible?, #null_assignable_to?, #numeric_constant_fits_type?, #opaque_type?, #own_to_raw_pointer_compatibility?, #own_type?, #owned_referent_type, #pointee_type, #pointer_type?, #proc_type?, #quat_vec4_layout_compatible?, #ref_lifetime, #ref_type?, #ref_type_without_lifetime?, #referenced_type, #same_external_opaque_c_name?, #same_external_opaque_handle_pointer_compatibility?, #string_builder_ref_type?, #string_builder_type?, #struct_with_target_type?, #task_root_proc_type?, #task_type?, #value_fits_integer_type?, #void_pointer_type?

Constructor Details

#initialize(ast, imported_modules: {}, allow_missing_imports: false, path: nil, global_import_index: {}) ⇒ Checker

Returns a new instance of Checker.



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 140

def initialize(ast, imported_modules: {}, allow_missing_imports: false, path: nil, global_import_index: {})
  @path = path
  @allow_missing_imports = allow_missing_imports
  @ctx = ModuleContext.new(
    ast:,
    module_name: ast.module_name&.to_s,
    module_kind: ast.module_kind,
    imported_modules:,
    global_import_index:,
    const_declarations: ast.declarations.grep(AST::ConstDecl).each_with_object({}) { |decl, result| result[decl.name] = decl },
  )
  @null_type = Types::Null.new
  @error_type = Types::Error.new
  @loop_depth = 0
  @unsafe_depth = 0
  @compile_time_depth = 0
  @foreign_mapping_depth = 0
  @async_function_depth = 0
  @checked_function_bindings = {}
  @checking_function_bindings = {}
  @evaluating_const_values = []
  @evaluated_const_values = {}
  @error_node_stack = []
  @local_completion_frames = []
  @active_local_completion_stack = []
  @resolved_expr_types = {}
  @resolved_call_kinds = {}
  @const_values = {}
  @next_binding_id = 1
  @binding_name_by_id = {}
  @binding_type_by_id = {}
  @identifier_binding_ids = {}
  @declaration_binding_ids = {}
  @mutating_argument_identifier_ids = {}
  @mutable_lvalue_argument_identifier_ids = {}
  @editable_receiver_expression_ids = {}
  @preassigned_local_binding_ids = {}
  @nullability_flow_result = nil
  @unsafe_statement_lines = []
  @callable_value_identifier_sites = {}
  @callable_value_member_access_sites = {}
  @required_unsafe_lines = []
  @uses_parallel_for = false
  @current_specialization_owner = nil
  @return_context_stack = []
end

Instance Attribute Details

#ctx ⇒ Object (readonly)

Returns the value of attribute ctx.



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 134

def ctx
  @ctx
end

Instance Method Details

#addressable_storage_expression?(expression, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 950

def addressable_storage_expression?(expression, scopes:)
  case expression
  when AST::Identifier
    true
  when AST::MemberAccess, AST::IndexAccess
    addressable_storage_expression?(expression.receiver, scopes:)
  when AST::Call
    return false unless expression.arguments.length == 1 && expression.arguments.first.name.nil?

    read_call?(expression) && ref_type?(infer_expression(expression.arguments.first.value, scopes:))
  else
    false
  end
end

#aggregate_display_name(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 831

def aggregate_display_name(type)
  type.is_a?(Types::StructInstance) ? type.to_s : type.name
end

#aggregate_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 701

def aggregate_type?(type)
  type.is_a?(Types::Struct) || type.is_a?(Types::Tuple) || span_type?(type) || string_view_type?(type) || task_type?(type) || vector_type?(type) || matrix_type?(type) || quaternion_type?(type)
end

#allocate_binding_id ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1380

def allocate_binding_id
  id = @next_binding_id
  @next_binding_id += 1
  id
end

#apply_continuation_refinements!(scopes, refinements) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 14

def apply_continuation_refinements!(scopes, refinements)
  return if refinements.nil? || refinements.empty?

  scopes.replace(scopes_with_refinements(scopes, refinements))
end

#apply_nullability_continuation_refinements!(scopes, next_stmt) ⇒ Object

After processing a statement, apply ControlFlow-derived non-null refinements to the scopes so the next statement benefits from cross-branch narrowing.



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 74

def apply_nullability_continuation_refinements!(scopes, next_stmt)
  return unless @nullability_flow_result

  nonnull_binding_ids = @nullability_flow_result.nonnull_before(next_stmt)
  return if nonnull_binding_ids.empty?

  refinements = {}
  nonnull_binding_ids.each do |binding_id|
    next unless binding_id.is_a?(Integer)

    name = @binding_name_by_id[binding_id]
    next unless name

    binding = lookup_value(name, scopes)
    next unless binding&.id == binding_id
    next unless binding&.storage_type.is_a?(Types::Nullable)

    refinements[name] = binding.storage_type.base
  end
  apply_continuation_refinements!(scopes, refinements) unless refinements.empty?
end

#argument_types_compatible?(actual_type, expected_type, external:, expression: nil, scopes: nil, contextual_int_to_float: false) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 65

def argument_types_compatible?(actual_type, expected_type, external:, expression: nil, scopes: nil, contextual_int_to_float: false)
  return true if types_compatible?(actual_type, expected_type, expression:, scopes:, external_numeric: external, contextual_int_to_float:)
  return true if external && external_void_pointer_argument_compatibility?(actual_type, expected_type)
  return true if external && extern_enum_integer_argument_compatibility?(actual_type, expected_type)
  if external && foreign_mapping_context? && foreign_identity_projection_compatible?(actual_type, expected_type)
    return false if actual_type == @ctx.types.fetch("cstr") && char_pointer_type?(expected_type)

    return true
  end

  false
end

#array_element_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 730

def array_element_type(type)
  return unless array_type?(type)

  type.arguments.first
end

#array_length(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 736

def array_length(type)
  return unless array_type?(type)

  type.arguments[1].value
end

#array_to_span_call_argument_compatible?(actual_type, expected_type, expression:, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1223

def array_to_span_call_argument_compatible?(actual_type, expected_type, expression:, scopes:)
  return false unless expected_type.is_a?(Types::Span)

  if array_type?(actual_type)
    return false unless array_element_type(actual_type) == expected_type.element_type

    infer_addr_source_type(expression, scopes:)
    record_mutable_lvalue_argument_identifier(expression)
    return true
  end

  if str_buffer_type?(actual_type)
    return false unless expected_type.element_type == @ctx.types.fetch("char")

    infer_addr_source_type(expression, scopes:)
    record_mutable_lvalue_argument_identifier(expression)
    return true
  end

  false
rescue SemanticError
  false
end

#array_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 725

def array_type?(type)
  type.is_a?(Types::GenericInstance) && type.name == "array" && type.arguments.length == 2 &&
    !type.arguments.first.is_a?(Types::LiteralTypeArg) && type.arguments[1].is_a?(Types::LiteralTypeArg)
end

#assignable_receiver?(receiver_expression, scopes) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1355

def assignable_receiver?(receiver_expression, scopes)
  infer_lvalue_receiver(receiver_expression, scopes:, allow_ref_identifier: true, allow_pointer_identifier: true, require_mutable_pointer: true)
  true
rescue SemanticError
  false
end

#atomic_element_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 759

def atomic_element_type(type)
  type.arguments.first
end

#atomic_method_kind(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 654

def atomic_method_kind(receiver_type, name)
  return unless atomic_type?(receiver_type)

  ATOMIC_METHOD_KINDS[name]
end

#atomic_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 755

def atomic_type?(type)
  type.is_a?(Types::GenericInstance) && type.name == "atomic" && type.arguments.length == 1
end

#attribute_binding_for_handle_expression(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 966

def attribute_binding_for_handle_expression(expression)
  return unless expression.is_a?(AST::Call)
  return unless expression.callee.is_a?(AST::Identifier) && expression.callee.name == "attribute_of"
  return unless expression.arguments.length == 2 && expression.arguments.none?(&:name)

  resolve_attribute_name_argument(expression.arguments[1].value)
end

#attribute_presence_guard_active?(scopes, key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 43

def attribute_presence_guard_active?(scopes, key)
  scopes.any? { |scope| scope.key?(key) }
end

#attribute_presence_key_from_call(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 175

def attribute_presence_key_from_call(expression, scopes:)
  target = resolve_reflection_target_argument(expression.arguments.first.value, scopes:)
  binding = resolve_attribute_name_argument(expression.arguments[1].value)
  validate_attribute_target_compatibility!(target, binding)
  attribute_presence_refinement_key(target, binding)
rescue SemanticError
  nil
end

#attribute_presence_refinement_key(target, binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 39

def attribute_presence_refinement_key(target, binding)
  AttributePresenceKey.new(target, binding.module_name, binding.name)
end

#attribute_target_kind(target) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1638

def attribute_target_kind(target)
  case target
  when Types::StructHandle then :struct
  when Types::FieldHandle then :field
  when Types::CallableHandle then :callable
  else
    raise_sema_error("unsupported attribute reflection target #{target}")
  end
end

#automatic_foreign_cstr_list_temp_needed?(parameter) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1216

def automatic_foreign_cstr_list_temp_needed?(parameter)
  return false unless parameter.type.is_a?(Types::Span) && parameter.type.element_type == @ctx.types.fetch("str")
  return false unless parameter.boundary_type.is_a?(Types::Span)

  boundary_element_type = parameter.boundary_type.element_type
  boundary_element_type == @ctx.types.fetch("cstr") || char_pointer_type?(boundary_element_type)
end

#automatic_foreign_cstr_temp_needed?(parameter, expression, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1224

def automatic_foreign_cstr_temp_needed?(parameter, expression, scopes:)
  return false unless parameter.boundary_type == @ctx.types.fetch("cstr") && parameter.type == @ctx.types.fetch("str")
  return false if expression.is_a?(AST::StringLiteral) && !expression.cstring

  infer_expression(expression, scopes:) != @ctx.types.fetch("cstr")
end

#binding_resolution_snapshot ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1369

def binding_resolution_snapshot
  BindingResolution.new(
    identifier_binding_ids: @identifier_binding_ids.dup.freeze,
    declaration_binding_ids: @declaration_binding_ids.dup.freeze,
    mutating_argument_identifier_ids: @mutating_argument_identifier_ids.dup.freeze,
    editable_receiver_expression_ids: @editable_receiver_expression_ids.dup.freeze,
    mutable_lvalue_argument_identifier_ids: @mutable_lvalue_argument_identifier_ids.dup.freeze,
    binding_types: @binding_type_by_id.dup.freeze,
  )
end

#bitwise_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 414

def bitwise_type?(type)
  type.respond_to?(:bitwise?) && type.bitwise?
end

#build_analysis ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 6

def build_analysis
  Analysis.new(
    ast: @ctx.ast,
    module_name: @ctx.module_name,
    module_kind: @ctx.module_kind,
    directives: @ctx.ast.directives,
    imports: @ctx.imports,
    types: @ctx.types,
    interfaces: @ctx.interfaces,
    attributes: snapshot_attributes,
    attribute_applications: snapshot_attribute_applications,
    values: @ctx.top_level_values,
    functions: @ctx.top_level_functions,
    methods: snapshot_methods,
    implemented_interfaces: snapshot_implemented_interfaces,
    local_completion_frames: @local_completion_frames.dup.freeze,
    binding_resolution: binding_resolution_snapshot,
    callable_value_identifier_sites: @callable_value_identifier_sites.dup.freeze,
    callable_value_member_access_sites: @callable_value_member_access_sites.dup.freeze,
    required_unsafe_lines: @required_unsafe_lines.uniq.freeze,
    uses_parallel_for: @uses_parallel_for,
    resolved_expr_types: @resolved_expr_types.dup.freeze,
    resolved_call_kinds: @resolved_call_kinds.dup.freeze,
    const_values: @const_values.dup.freeze,
  )
end

#builtin_attribute_handle_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 98

def builtin_attribute_handle_type
  Types::BUILTIN_ATTRIBUTE_HANDLE_TYPE
end

#builtin_callable_handle_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 94

def builtin_callable_handle_type
  Types::BUILTIN_CALLABLE_HANDLE_TYPE
end

#builtin_event_error_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 82

def builtin_event_error_type
  Types::Enum.new("EventError").define_members(@ctx.types.fetch("int"), ["full"]).define_member_values("full" => 0)
end

#builtin_field_handle_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 90

def builtin_field_handle_type
  Types::BUILTIN_FIELD_HANDLE_TYPE
end

#builtin_member_handle_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 102

def builtin_member_handle_type
  Types::BUILTIN_MEMBER_HANDLE_TYPE
end

#builtin_struct_handle_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 86

def builtin_struct_handle_type
  Types::BUILTIN_STRUCT_HANDLE_TYPE
end

#builtin_subscription_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 78

def builtin_subscription_type
  Types::Subscription.new
end

#builtin_type_meta_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 106

def builtin_type_meta_type
  Types::BUILTIN_TYPE_META_TYPE
end

#c_natively_equality_comparable_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 847

def c_natively_equality_comparable_type?(type)
  return true if type.is_a?(Types::Primitive)
  return true if type.is_a?(Types::EnumBase)
  return true if type.is_a?(Types::Opaque)
  return true if type.is_a?(Types::Nullable)
  return true if type.is_a?(Types::Null)
  return true if type.is_a?(Types::Function)
  return true if type.is_a?(Types::Error)
  return true if type.is_a?(Types::StringView)
  return true if pointer_type?(type)
  return true if ref_type?(type)
  return true if type.is_a?(Types::Variant)
  return true if type.is_a?(Types::VariantArmPayload)

  false
end

#call_argument_compatible?(actual_type, expected_type, scopes:, external:, expression: nil) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 6

def call_argument_compatible?(actual_type, expected_type, scopes:, external:, expression: nil)
  return true if array_to_span_call_argument_compatible?(actual_type, expected_type, expression:, scopes:)
  return true if argument_types_compatible?(actual_type, expected_type, external:, expression:, scopes:, contextual_int_to_float: !external)
  return true if implicit_ref_argument_compatible?(actual_type, expected_type, expression, scopes)
  return true if direct_task_to_proc_argument_compatible?(actual_type, expected_type)
  return true if direct_function_to_proc_argument_compatible?(actual_type, expected_type, expression, scopes)

  false
end

#callable_receiver_type_for_specialization(callee, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 92

def callable_receiver_type_for_specialization(callee, scopes:)
  return unless callee.is_a?(AST::MemberAccess)

  resolve_type_expression(callee.receiver)
end

#callable_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 418

def callable_type?(type)
  type.is_a?(Types::Function) || type.is_a?(Types::Proc)
end

#canonicalize_call_arguments(arguments, params, context_name, binding = nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 1013

def canonicalize_call_arguments(arguments, params, context_name, binding = nil)
  return arguments unless arguments.any?(&:name)

  named_seen = false
  by_position = Array.new(params.length)
  param_names = params.map(&:name)

  arguments.each_with_index do |arg, _idx|
    if arg.name
      named_seen = true
      raise_sema_error("duplicate named argument '#{arg.name}' in call to #{context_name}") if by_position.any? { |slot| slot&.name == arg.name }
      param_idx = param_names.index(arg.name)
      raise_sema_error("unknown parameter '#{arg.name}' for #{context_name}") unless param_idx
      by_position[param_idx] = arg
    else
      raise_sema_error("positional argument after named argument in call to #{context_name}") if named_seen
      param_idx = _idx
      raise_sema_error("#{context_name} expects #{params.length} arguments, got #{arguments.length}") if param_idx >= params.length
      by_position[param_idx] = arg
    end
  end

  fill_parameter_defaults!(by_position, params, binding, context_name)

  by_position.reject(&:nil?)
end

#cast_numeric_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 191

def cast_numeric_type(type)
  return type if type.is_a?(Types::Primitive) && (type.numeric? || type.name == "bool")
  return type.backing_type if type.is_a?(Types::EnumBase) && type.backing_type.numeric?
  return type if char_type?(type)
  return type.backing_type if type.is_a?(Types::EnumBase) && char_type?(type.backing_type)

  nil
end

#castable_primitive?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 477

def castable_primitive?(type)
  return castable_primitive?(type.base) if type.is_a?(Types::Nullable)

  type.is_a?(Types::Primitive) || type.is_a?(Types::Enum) || type.is_a?(Types::Flags)
end

#catch_structural ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 323

def catch_structural
  yield
rescue SemanticError => e
  @structural_errors << e
end

#cfg_block_always_terminates?(statements) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 55

def cfg_block_always_terminates?(statements)
  ControlFlow::Termination.block_always_terminates?(statements, ignore_name: ->(_name) { false })
end

#char_array_removed_text_method?(receiver_type, name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 769

def char_array_removed_text_method?(receiver_type, name)
  return unless char_array_text_type?(receiver_type)

  name == "as_str" || name == "as_cstr"
end

#char_array_text_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 742

def char_array_text_type?(type)
  array_type?(type) && array_element_type(type) == @ctx.types.fetch("char")
end

#check ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 187

def check
  install_builtin_types
  install_builtin_attributes
  install_imports
  install_prelude_types
  declare_named_types
  resolve_generic_type_param_constraints
  resolve_type_aliases
  declare_attributes
  resolve_aggregate_fields
  resolve_enum_members
  resolve_variant_arms
  collect_emit_declarations
  declare_top_level_values
  check_attribute_applications
  declare_functions
  check_interface_conformances
  check_top_level_values
  finalize_top_level_const_values
  check_top_level_static_asserts
  check_functions

  build_analysis
end

#check_adapt_call(interface, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 974

def check_adapt_call(interface, arguments, scopes:)
  raise_sema_error("adapt does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("adapt expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  argument = arguments.first
  concrete_type = infer_expression(argument.value, scopes:)
  concrete_type = referenced_type(concrete_type) if ref_type?(concrete_type)
  unless concrete_type.is_a?(Types::Struct) || concrete_type.is_a?(Types::Opaque) || concrete_type.is_a?(Types::StructInstance)
    raise_sema_error("adapt requires a struct or opaque type, got #{concrete_type}")
  end

  unless type_implements_interface?(concrete_type, interface)
    raise_sema_error("#{concrete_type} does not implement #{interface.name}")
  end

  Types::Dyn.new(interface, interface.type_arguments || [])
end

#check_aggregate_construction(struct_type, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 47

def check_aggregate_construction(struct_type, arguments, scopes:)
  require_unsafe!("str construction requires unsafe") if struct_type.is_a?(Types::StringView)

  check_aggregate_field_arguments(struct_type, arguments, scopes:, context: "aggregate construction")
  struct_type
end

#check_aggregate_field_arguments(struct_type, arguments, scopes:, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 77

def check_aggregate_field_arguments(struct_type, arguments, scopes:, context:)
  display_name = aggregate_display_name(struct_type)

  raise_sema_error("#{context} for #{display_name} requires named arguments") unless arguments.all?(&:name)

  provided = {}
  arguments.each do |argument|
    field_type = struct_type.field(argument.name)
    raise_sema_error("unknown field #{display_name}.#{argument.name}") unless field_type
    raise_sema_error("duplicate field #{display_name}.#{argument.name}") if provided.key?(argument.name)

    actual_type = infer_expression(argument.value, scopes:, expected_type: field_type)
    ensure_assignable!(
      actual_type,
      field_type,
      "field #{display_name}.#{argument.name} expects #{field_type}, got #{actual_type}",
      expression: argument.value,
      external_numeric: struct_type.respond_to?(:external) && struct_type.external,
      external_pointer_null: struct_type.respond_to?(:external) && struct_type.external,
      contextual_int_to_float: contextual_int_to_float_target?(field_type),
    )
    provided[argument.name] = true
  end
end

#check_array_construction(array_type, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 138

def check_array_construction(array_type, arguments, scopes:)
  raise_sema_error("array construction does not support named arguments") if arguments.any?(&:name)

  element_type = array_element_type(array_type)
  length = array_length(array_type)
  raise_sema_error("array expects at most #{length} elements, got #{arguments.length}") if arguments.length > length

  arguments.each do |argument|
    actual_type = infer_expression(argument.value, scopes:, expected_type: element_type)
    ensure_assignable!(
      actual_type,
      element_type,
      "array element expects #{element_type}, got #{actual_type}",
      expression: argument.value,
    )
  end

  array_type
end

#check_assignment(statement, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 469

def check_assignment(statement, scopes:)
  if statement.operator == "=" &&
     statement.target.is_a?(AST::IndexAccess) &&
     statement.target.index.is_a?(AST::RangeExpr)
    return check_range_index_assignment(statement, scopes:)
  end

  target_type = infer_lvalue(statement.target, scopes:)
  raise_sema_error("cannot assign to non-copyable event storage type #{target_type}") if noncopyable_event_storage_type?(target_type)

  validate_consuming_foreign_expression!(statement.value, scopes:, root_allowed: false)
  value_type = infer_expression(statement.value, scopes:, expected_type: target_type)

  case statement.operator
  when "="
    ensure_assignable!(
      value_type,
      target_type,
      "cannot assign #{value_type} to #{target_type}",
      expression: statement.value,
      external_numeric: external_numeric_assignment_target?(statement.target, scopes:),
      contextual_int_to_float: contextual_int_to_float_target?(target_type),
      line: statement.line, column: statement.column,
    )
  when "+=", "-=", "*=", "/="
    binary_op = statement.operator[0...-1]
    if (result_type = vector_arithmetic_result(binary_op, target_type, value_type))
      raise_sema_error("operator #{statement.operator} on #{target_type} and #{value_type} produces #{result_type}, expected #{target_type}") unless result_type == target_type
    else
      raise_sema_error("operator #{statement.operator} requires matching numeric types, got #{target_type} and #{value_type}") unless target_type.numeric? && value_type.numeric?

      ensure_assignable!(
        value_type,
        target_type,
        "operator #{statement.operator} requires matching numeric types, got #{target_type} and #{value_type}",
        expression: statement.value,
        contextual_int_to_float: contextual_int_to_float_target?(target_type),
        line: statement.line, column: statement.column,
      )
    end
  when "%="
    unless common_integer_type(target_type, value_type) == target_type || simd_mod_result(target_type, value_type)
      raise_sema_error("operator #{statement.operator} requires compatible integer types, got #{target_type} and #{value_type}")
    end
  when "&=", "|=", "^="
    unless (target_type == value_type && bitwise_type?(target_type)) || (simd_type?(target_type) && simd_type?(value_type) && target_type == value_type)
      raise_sema_error("operator #{statement.operator} requires matching integer or flags types, got #{target_type} and #{value_type}")
    end
  when "<<=", ">>="
    unless (target_type.is_a?(Types::Primitive) && target_type.integer? && value_type.is_a?(Types::Primitive) && value_type.integer?) || simd_shift_result(target_type, value_type)
      raise_sema_error("operator #{statement.operator} requires integer operands, got #{target_type} and #{value_type}")
    end
  else
    raise_sema_error("unsupported assignment operator #{statement.operator}")
  end
end

#check_atomic_method_call(kind, receiver_type, receiver, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 666

def check_atomic_method_call(kind, receiver_type, receiver, arguments, scopes:)
  elem_type = atomic_element_type(receiver_type)
  raise_sema_error("atomic methods do not support named arguments") if arguments.any?(&:name)

  case kind
  when :atomic_load
    raise_sema_error("load expects 0 arguments, got #{arguments.length}") unless arguments.empty?
    elem_type
  when :atomic_store
    raise_sema_error("store expects 1 argument, got #{arguments.length}") unless arguments.length == 1
    record_editable_receiver_expression(receiver)
    raise_sema_error("cannot call editable method store on an immutable receiver") unless assignable_receiver?(receiver, scopes)
    arg_type = infer_expression(arguments.first.value, scopes:, expected_type: elem_type)
    ensure_assignable!(arg_type, elem_type, "store expects #{elem_type}, got #{arg_type}")
    @ctx.types.fetch("void")
  when :atomic_add, :atomic_sub, :atomic_exchange
    raise_sema_error("#{kind.to_s.delete_prefix("atomic_")} expects 1 argument, got #{arguments.length}") unless arguments.length == 1
    record_editable_receiver_expression(receiver)
    raise_sema_error("cannot call editable method #{kind.to_s.delete_prefix("atomic_")} on an immutable receiver") unless assignable_receiver?(receiver, scopes)
    arg_type = infer_expression(arguments.first.value, scopes:, expected_type: elem_type)
    ensure_assignable!(arg_type, elem_type, "#{kind.to_s.delete_prefix("atomic_")} expects #{elem_type}, got #{arg_type}")
    elem_type
  when :atomic_compare_exchange
    raise_sema_error("compare_exchange expects 2 arguments, got #{arguments.length}") unless arguments.length == 2
    record_editable_receiver_expression(receiver)
    raise_sema_error("cannot call editable method compare_exchange on an immutable receiver") unless assignable_receiver?(receiver, scopes)
    exp_type = infer_expression(arguments[0].value, scopes:, expected_type: elem_type)
    des_type = infer_expression(arguments[1].value, scopes:, expected_type: elem_type)
    ensure_assignable!(exp_type, elem_type, "compare_exchange expected type #{elem_type}, got #{exp_type}")
    ensure_assignable!(des_type, elem_type, "compare_exchange desired type #{elem_type}, got #{des_type}")
    @ctx.types.fetch("bool")
  end
end

#check_attribute_applications ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/attributes.rb', line 6

def check_attribute_applications
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      case decl
      when AST::StructDecl
        packed, alignment = check_decl_attribute_applications!(decl.attributes, target_kind: :struct, target_label: "struct #{decl.name}", target_node: decl)
        @ctx.types.fetch(decl.name).set_layout(packed:, alignment:)

        decl.fields.each do |field|
          with_error_node(field) do
            if raw_module? && field.attributes.any?
              raise_sema_error("attributes are not allowed on fields in external files")
            end

            check_decl_attribute_applications!(field.attributes, target_kind: :field, target_label: "field #{decl.name}.#{field.name}", target_node: field)
          end
        end
      when AST::FunctionDef, AST::ExternFunctionDecl, AST::ForeignFunctionDecl
        check_decl_attribute_applications!(decl.attributes, target_kind: :callable, target_label: "callable #{decl.name}", target_node: decl)
      when AST::InterfaceDecl
        decl.methods.each do |method|
          with_error_node(method) do
            check_decl_attribute_applications!(method.attributes, target_kind: :callable, target_label: "callable #{decl.name}.#{method.name}", target_node: method)
          end
        end
      when AST::ExtendingBlock
        decl.methods.each do |method|
          with_error_node(method) do
            check_decl_attribute_applications!(method.attributes, target_kind: :callable, target_label: "callable #{decl.type_name}.#{method.name}", target_node: method)
          end
        end
      when AST::ConstDecl
        check_decl_attribute_applications!(decl.attributes, target_kind: :const, target_label: "const #{decl.name}", target_node: decl)
      when AST::EventDecl
        check_decl_attribute_applications!(decl.attributes, target_kind: :event, target_label: "event #{decl.name}", target_node: decl)
      when AST::UnionDecl
        check_decl_attribute_applications!(decl.attributes, target_kind: :union, target_label: "union #{decl.name}", target_node: decl)
      when AST::EnumDecl
        check_decl_attribute_applications!(decl.attributes, target_kind: :enum, target_label: "enum #{decl.name}", target_node: decl)
      when AST::FlagsDecl
        check_decl_attribute_applications!(decl.attributes, target_kind: :flags, target_label: "flags #{decl.name}", target_node: decl)
      when AST::VariantDecl
        check_decl_attribute_applications!(decl.attributes, target_kind: :variant, target_label: "variant #{decl.name}", target_node: decl)
      end
    end
  end
end

#check_attribute_arg_call(expected_type, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 940

def check_attribute_arg_call(expected_type, arguments, scopes:)
  raise_sema_error("attribute_arg does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("attribute_arg expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  handle_value = evaluate_compile_time_const_value(arguments.first.value, scopes:)
  parameter_source = if handle_value.is_a?(Types::AttributeHandle)
    [handle_value.attribute_name, handle_value.params]
  else
    handle_type = infer_expression(arguments.first.value, scopes:)
    raise_sema_error("attribute_arg expects an attribute handle") unless handle_type == builtin_attribute_handle_type

    binding = attribute_binding_for_handle_expression(arguments.first.value)
    raise_sema_error("attribute_arg expects an attribute handle") unless binding

    [binding.name, binding.params]
  end

  param_name = reflection_identifier_name(arguments[1].value, context: "attribute_arg")
  attribute_name, params = parameter_source
  parameter = params.find { |candidate| candidate.name == param_name }
  raise_sema_error("attribute #{attribute_name} has no parameter #{param_name}") unless parameter
  raise_sema_error("attribute_arg[#{expected_type}] does not match declared type #{parameter.type} for #{attribute_name}.#{param_name}") unless parameter.type == expected_type

  expected_type
end

#check_attribute_arguments!(binding, application) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/attributes.rb', line 100

def check_attribute_arguments!(binding, application)
  params = binding.params
  arguments = application.arguments

  if params.empty?
    raise_sema_error("attribute #{binding.name} does not take arguments") if arguments.any?

    return {}
  end

  bound_arguments = {}
  next_position = 0

  arguments.each do |argument|
    param = if argument.name
      params.find { |candidate| candidate.name == argument.name }.tap do |candidate|
        raise_sema_error("unknown attribute argument #{binding.name}.#{argument.name}") unless candidate
      end
    else
      while next_position < params.length && bound_arguments.key?(params[next_position].name)
        next_position += 1
      end

      raise_sema_error("attribute #{binding.name} expects #{params.length} arguments, got #{arguments.length}") if next_position >= params.length

      param = params[next_position]
      next_position += 1
      param
    end

    raise_sema_error("duplicate attribute argument #{binding.name}.#{param.name}") if bound_arguments.key?(param.name)

    bound_arguments[param.name] = argument.value
  end

  missing = params.reject { |param| bound_arguments.key?(param.name) }
  unless missing.empty?
    names = missing.map(&:name).join(", ")
    raise_sema_error("attribute #{binding.name} is missing required arguments: #{names}")
  end

  params.each_with_object({}) do |param, values|
    argument_expression = bound_arguments.fetch(param.name)
    actual_type = infer_expression(argument_expression, scopes: [], expected_type: param.type)
    ensure_assignable!(
      actual_type,
      param.type,
      "attribute #{binding.name} argument #{param.name} expects #{param.type}, got #{actual_type}",
      expression: argument_expression,
    )

    const_value = evaluate_compile_time_const_value(argument_expression)
    raise_sema_error("attribute #{binding.name} argument #{param.name} must be a compile-time constant") if const_value.nil?

    values[param.name] = const_value
  end
end

#check_attribute_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 925

def check_attribute_of_call(arguments, scopes:)
  raise_sema_error("attribute_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("attribute_of expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  target = resolve_reflection_target_argument(arguments.first.value, scopes:)
  binding = resolve_attribute_name_argument(arguments[1].value)
  validate_attribute_target_compatibility!(target, binding)

  application = find_attribute_application(target, binding)
  unless application || attribute_presence_guard_active?(scopes, attribute_presence_refinement_key(target, binding))
    raise_sema_error("attribute #{qualified_attribute_name(binding)} is not applied to #{target}")
  end

  builtin_attribute_handle_type
end

#check_block(statements, scopes:, return_type:, allow_return: true) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 6

def check_block(statements, scopes:, return_type:, allow_return: true)
  statements ||= []
  with_return_context(return_type, allow_return:) do
    with_nested_scope(scopes) do |nested_scopes|
      with_type_resolution_scopes(nested_scopes) do
        statements.each_with_index do |statement, idx|
          begin
            record_local_completion_snapshot(
              statement.line,
              statement.column || 0,
              nested_scopes,
            )
            refinements = check_statement(statement, scopes: nested_scopes, return_type:, allow_return:)
            apply_continuation_refinements!(nested_scopes, refinements)
            if @nullability_flow_result && idx + 1 < statements.length
              apply_nullability_continuation_refinements!(nested_scopes, statements[idx + 1])
            end
            end_line = statement_end_line(statement)
            # When the statement spans multiple lines (e.g. let … else:),
            # record an extra snapshot at the declaration line so that
            # hover and completion lookups on the declaration line itself
            # can still find the new binding.
            if end_line && statement.line && end_line > statement.line
              record_local_completion_snapshot(
                statement.line,
                statement.column || 0,
                nested_scopes,
              )
            end
            record_local_completion_snapshot(end_line, 1_000_000, nested_scopes)
          rescue SemanticError => e
            if @collecting_errors
              @structural_errors << e
              next
            end

            raise e unless e.line.nil?

            stmt_line = statement.line
            raise e if stmt_line.nil?

            raise_sema_error(e.message, statement)
          end
        end
      end
    end
  end
end

#check_block_body_const(decl) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 60

def check_block_body_const(decl)
  return unless decl.block_body

  last_stmt = decl.block_body.last
  unless last_stmt.is_a?(AST::ReturnStmt) && last_stmt.value
    raise_sema_error("block-bodied const must end with a return statement")
  end
end

#check_callable_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 908

def check_callable_of_call(arguments, scopes:)
  raise_sema_error("callable_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("callable_of expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  evaluate_callable_of_call(arguments, scopes:)
  builtin_callable_handle_type
end

#check_callable_value_call(function_type, arguments, scopes:, callee_expression:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 823

def check_callable_value_call(function_type, arguments, scopes:, callee_expression:)
  arguments = canonicalize_call_arguments(arguments, function_type.params, describe_expression(callee_expression))

  unless call_arity_matches?(function_type, arguments.length)
    raise_sema_error(arity_error_message(function_type, describe_expression(callee_expression), arguments.length))
  end

  function_type.params.each_with_index do |parameter, index|
    argument = arguments.fetch(index)
    actual_type = infer_expression(argument.value, scopes:, expected_type: parameter.type)
    unless call_argument_compatible?(actual_type, parameter.type, scopes:, external: false, expression: argument.value)
      suggestion = explicit_cast_suggestion(actual_type, parameter.type)
      raise_sema_error("argument #{parameter.name || index} to #{describe_expression(callee_expression)} expects #{parameter.type}, got #{actual_type}", argument, suggestion:)
    end
  end

  arguments.drop(function_type.params.length).each do |argument|
    infer_expression(argument.value, scopes:)
  end
end

#check_cast_call(target_type, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 158

def check_cast_call(target_type, arguments, scopes:)
  raise_sema_error("cast requires exactly one argument") unless arguments.length == 1
  raise_sema_error("cast does not support named arguments") if arguments.first.name

  source_type = infer_expression(arguments.first.value, scopes:)
  if source_type == target_type
    return target_type
  end

  if pointer_cast?(source_type, target_type)
    expression = arguments.first.value
    require_unsafe!("pointer cast requires unsafe", line: source_line(expression), column: source_column(expression))

    return target_type
  end

  if ref_to_pointer_cast?(source_type, target_type)
    expression = arguments.first.value
    require_unsafe!("ref to pointer cast requires unsafe", line: source_line(expression), column: source_column(expression))

    return target_type
  end

  source_numeric_type = cast_numeric_type(source_type)
  target_numeric_type = cast_numeric_type(target_type)

  unless source_numeric_type && target_numeric_type
    raise_sema_error("cast requires compatible types, got #{source_type} -> #{target_type}")
  end

  target_type
end

#check_collecting_errors ⇒ Object

Like check, but collects per-function errors instead of raising at first. Structural phases (imports, type resolution, declaration) collect errors per declaration so that the maximum number of diagnostics are surfaced. Returns { analysis: Analysis, errors: [SemanticError] }.



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 274

def check_collecting_errors
  @collecting_errors = true
  @structural_errors = []

  catch_structural { install_builtin_types }
  catch_structural { install_builtin_attributes }
  catch_structural { install_imports }
  catch_structural { install_prelude_types }
  catch_structural { declare_named_types }
  catch_structural { resolve_generic_type_param_constraints }
  catch_structural { resolve_type_aliases }
  catch_structural { declare_attributes }
  catch_structural { resolve_aggregate_fields }
  catch_structural { resolve_enum_members }
  catch_structural { resolve_variant_arms }
  catch_structural { collect_emit_declarations }
  catch_structural { declare_top_level_values }
  catch_structural { check_attribute_applications }
  catch_structural { declare_functions }
  catch_structural { check_interface_conformances }

  errors = @structural_errors.dup

  begin
    check_top_level_values
  rescue SemanticError => e
    errors << e
  end
  errors.concat(@structural_errors.drop(errors.length))

  begin
    finalize_top_level_const_values
  rescue SemanticError => e
    errors << e
  end

  begin
    check_top_level_static_asserts
  rescue SemanticError => e
    errors << e
  end

  check_functions_collecting(errors)

  analysis = build_analysis

  { analysis: analysis, errors: errors.uniq { |e| [e.message, e.line, e.column, e.length] } }
end

#check_const_ptr_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 879

def check_const_ptr_of_call(arguments, scopes:)
  raise_sema_error("const_ptr_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("const_ptr_of expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  source_type = infer_ro_addr_source_type(arguments.first.value, scopes:)
  const_pointer_to(source_type)
end

#check_decl_attribute_applications!(applications, target_kind:, target_label:, target_node:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/attributes.rb', line 54

def check_decl_attribute_applications!(applications, target_kind:, target_label:, target_node:)
  seen = {}
  packed = false
  alignment = nil
  resolved_applications = []

  applications.each do |application|
    with_error_node(application) do
      binding = resolve_attribute_binding(application.name)

      if raw_module?
        raise_sema_error("only built-in struct attributes are allowed in external files") unless binding.builtin && target_kind == :struct
      end

      unless binding.targets.include?(target_kind)
        raise_sema_error("attribute #{binding.name} cannot target #{target_kind}")
      end

      binding_key = [binding.module_name, binding.name]
      raise_sema_error("duplicate attribute #{binding.name} on #{target_label}") if seen.key?(binding_key)

      seen[binding_key] = true
      argument_values = check_attribute_arguments!(binding, application)
      argument_values = argument_values.freeze
      @ctx.attribute_application_bindings[application.object_id] = binding
      @ctx.validated_attribute_arguments[application.object_id] = argument_values
      resolved_applications << ResolvedAttributeApplication.new(binding:, argument_values:)

      case binding.name
      when "packed"
        packed = true
      when "align"
        bytes = argument_values.fetch("bytes")
        raise_sema_error("align(...) requires a positive alignment") unless bytes.is_a?(Integer) && bytes.positive?
        raise_sema_error("align(...) requires a power-of-two alignment, got #{bytes}") unless power_of_two?(bytes)

        alignment = bytes
      end
    end
  end

  @ctx.resolved_attribute_applications[target_node.object_id] = resolved_applications.freeze

  [packed, alignment]
end

#check_definite_assignment(binding) ⇒ Object

Raises:



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 6

def check_definite_assignment(binding)
  return unless binding.ast.respond_to?(:body)

  resolution = binding_resolution_snapshot
  graph = ControlFlow::Builder.new(
    binding_resolution: ControlFlow::BindingResolution.new(
      identifier_binding_ids: resolution.identifier_binding_ids,
      declaration_binding_ids: resolution.declaration_binding_ids,
      mutating_argument_identifier_ids: resolution.mutating_argument_identifier_ids,
    ),
    strict_binding_ids: true,
    local_decl_without_initializer_writes: true,
  ).build(binding.ast.body)

  local_declared_ids = Set.new
  graph.each_node do |node|
    node.writes_info.each do |write|
      origin = write[:origin]
      next unless %i[declaration for_binding match_binding].include?(origin)

      local_declared_ids << write[:binding_key]
    end
  end

  initially_assigned = binding.body_params.each_with_object(Set.new) do |param, set|
    set << param.id if param.id
  end
  # Any binding read but never defined in this function body is treated as
  # preassigned (for example module-level const/var bindings).
  initially_assigned.merge(graph.read_bindings - local_declared_ids)

  result = ControlFlow::DefiniteAssignment.solve(graph, initially_assigned:)
  first_issue = result.read_before_assignment.min_by do |issue|
    [issue.line || Float::INFINITY, issue.column || Float::INFINITY, issue.node_id]
  end
  return unless first_issue

  name = @binding_name_by_id[first_issue.binding_key] || first_issue.binding_key
  raise SemanticError.new(
    "read of '#{name}' before definite assignment",
    line: first_issue.line,
    column: first_issue.column,
    length: first_issue.length || name.to_s.length,
    path: @path,
  )
end

#check_dyn_method_call(method_binding, _receiver, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 992

def check_dyn_method_call(method_binding, _receiver, arguments, scopes:)
  raise_sema_error("#{method_binding.name} expects #{method_binding.params.length} arguments, got #{arguments.length}") unless arguments.length == method_binding.params.length

  method_binding.params.each_with_index do |param, index|
    actual_type = infer_expression(arguments[index].value, scopes:, expected_type: param.type)
    ensure_assignable!(
      actual_type,
      param.type,
      "argument #{index + 1} of #{method_binding.name} expects #{param.type}, got #{actual_type}",
      expression: arguments[index].value,
    )
  end
end

#check_emit_stmt(statement) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1214

def check_emit_stmt(statement)
  raise_sema_error("emit is only allowed inside const function or inline blocks") unless @compile_time_depth.positive?
end

#check_enum_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 584

def check_enum_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  each_enum_match_arm(statement, scrutinee_type, scopes:) do |arm, arm_scopes|
    check_block(arm.body, scopes: arm_scopes, return_type:, allow_return:)
  end
end

#check_equal_call(resolution, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 434

def check_equal_call(resolution, arguments, scopes:)
  raise_sema_error("equal does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("equal expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  arguments.each do |argument|
    validate_hash_operation_argument!(argument.value, resolution.target_type, scopes:, operation: "equal")
  end

  @ctx.types.fetch("bool")
end

#check_event_method_call(kind, receiver, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 517

def check_event_method_call(kind, receiver, arguments, scopes:)
  method_name = event_method_name(kind)
  receiver_type = infer_expression(receiver, scopes:)
  raise_sema_error("unknown method #{receiver_type}.#{method_name}") unless event_type?(receiver_type)

  raise_sema_error("#{method_name} does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("cannot call editable method #{receiver_type}.#{method_name} on an immutable receiver") unless event_receiver_mutable?(receiver, scopes:)
  if kind == :event_emit
    raise_sema_error("#{receiver_type}.emit is only available inside module #{receiver_type.module_name}") unless receiver_type.module_name == @ctx.module_name
  end

  case kind
  when :event_subscribe, :event_subscribe_once
    if arguments.length == 2 && arguments.none?(&:name)
      state_type = infer_expression(arguments[0].value, scopes:)
      unless pointer_type?(state_type)
        suggestion = if arguments[0].value.is_a?(AST::Identifier)
                       "use ptr_of(#{arguments[0].value.name})"
                     end
        raise_sema_error("first argument to #{receiver_type}.#{method_name} stateful overload must be a non-null pointer, got #{state_type}", arguments[0].value, suggestion:)
      end

      state_pointed_type = state_type.arguments.first
      expected_listener_type = event_stateful_listener_type(receiver_type, state_pointed_type)
      actual_listener_type = infer_expression(arguments[1].value, scopes:, expected_type: expected_listener_type)
      ensure_argument_assignable!(
        actual_listener_type,
        expected_listener_type,
        external: false,
        message: "listener argument to #{receiver_type}.#{method_name} expects #{expected_listener_type}, got #{actual_listener_type}",
        expression: arguments[1].value,
      )
    elsif arguments.length == 1
      listener_type = event_listener_type(receiver_type)
      actual_type = infer_expression(arguments.first.value, scopes:, expected_type: listener_type)
      ensure_argument_assignable!(
        actual_type,
        listener_type,
        external: false,
        message: "argument listener to #{receiver_type}.#{method_name} expects #{listener_type}, got #{actual_type}",
        expression: arguments.first.value,
      )
    else
      raise_sema_error("#{method_name} expects 1 or 2 arguments, got #{arguments.length}")
    end

    event_subscription_result_type
  when :event_unsubscribe
    raise_sema_error("unsubscribe expects 1 argument, got #{arguments.length}") unless arguments.length == 1

    actual_type = infer_expression(arguments.first.value, scopes:, expected_type: @ctx.types.fetch("Subscription"))
    ensure_argument_assignable!(
      actual_type,
      @ctx.types.fetch("Subscription"),
      external: false,
      message: "argument subscription to #{receiver_type}.unsubscribe expects Subscription, got #{actual_type}",
      expression: arguments.first.value,
    )

    @ctx.types.fetch("bool")
  when :event_emit
    if receiver_type.payload_type.nil?
      raise_sema_error("emit expects 0 arguments, got #{arguments.length}") unless arguments.empty?
    else
      raise_sema_error("emit expects 1 argument, got #{arguments.length}") unless arguments.length == 1

      actual_type = infer_expression(arguments.first.value, scopes:, expected_type: receiver_type.payload_type)
      ensure_argument_assignable!(
        actual_type,
        receiver_type.payload_type,
        external: false,
        message: "argument value to #{receiver_type}.emit expects #{receiver_type.payload_type}, got #{actual_type}",
        expression: arguments.first.value,
      )
    end

    @ctx.types.fetch("void")
  when :event_wait
    raise_sema_error("wait expects 0 arguments, got #{arguments.length}") unless arguments.empty?

    Types::Registry.task(event_wait_result_type(receiver_type))
  else
    raise_sema_error("unsupported event method #{kind}")
  end
end

#check_expr_const(decl) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 41

def check_expr_const(decl)
  binding = @ctx.top_level_values.fetch(decl.name)
  validate_consuming_foreign_expression!(decl.value, scopes: [], root_allowed: false)
  validate_hoistable_foreign_expression!(decl.value, scopes: [], root_hoistable: false)

  if binding.type == builtin_type_meta_type
    evaluate_compile_time_const_value(decl.value)
    return
  end

  actual_type = infer_expression(decl.value, scopes: [], expected_type: binding.type)
  ensure_assignable!(
    actual_type,
    binding.type,
    "cannot assign #{actual_type} to constant #{decl.name}: expected #{binding.type}",
    expression: decl.value,
  )
end

#check_expr_names(expr, scopes, binding, names) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 397

def check_expr_names(expr, scopes, binding, names)
  case expr
  when AST::Identifier
    check_generic_name(expr.name, scopes, binding, expr, names)
  when AST::MemberAccess
    check_expr_names(expr.receiver, scopes, binding, names)
  when AST::Call
    check_expr_names(expr.callee, scopes, binding, names)
    expr.arguments.each { |arg| check_expr_names(arg.value, scopes, binding, names) }
  when AST::BinaryOp
    check_expr_names(expr.left, scopes, binding, names)
    check_expr_names(expr.right, scopes, binding, names)
  when AST::UnaryOp
    check_expr_names(expr.operand, scopes, binding, names)
  when AST::IfExpr
    check_expr_names(expr.condition, scopes, binding, names)
    check_expr_names(expr.then_expression, scopes, binding, names)
    check_expr_names(expr.else_expression, scopes, binding, names)
  when AST::MatchExpr
    check_expr_names(expr.expression, scopes, binding, names)
    expr.arms.each do |arm|
      arm_names = names.dup
      arm_names.add(arm.binding_name) if arm.binding_name
      check_expr_names(arm.value, scopes, binding, arm_names)
    end
  when AST::IndexAccess
    check_expr_names(expr.receiver, scopes, binding, names)
    check_expr_names(expr.index, scopes, binding, names)
  when AST::Specialization
    check_expr_names(expr.callee, scopes, binding, names)
  when AST::PrefixCast
    check_expr_names(expr.expression, scopes, binding, names)
  when AST::AwaitExpr
    check_expr_names(expr.expression, scopes, binding, names)
  when AST::UnsafeExpr
    check_expr_names(expr.expression, scopes, binding, names)
  when AST::RangeExpr
    check_expr_names(expr.start_expr, scopes, binding, names) if expr.start_expr
    check_expr_names(expr.end_expr, scopes, binding, names) if expr.end_expr
  when AST::ExpressionList
    expr.elements.each { |elem| check_expr_names(elem, scopes, binding, names) }
  when AST::ProcExpr
    body_names = names.dup
    Array(expr.params).each { |p| body_names.add(p.name) if p.respond_to?(:name) }
    expr.body&.each { |s| check_stmt_names(s, scopes, binding, body_names) }
  when AST::DetachExpr
    check_expr_names(expr.body, scopes, binding, names)
  when AST::FormatExprPart
    check_expr_names(expr.expression, scopes, binding, names)
  when AST::IntegerLiteral, AST::FloatLiteral, AST::StringLiteral,
       AST::BooleanLiteral, AST::NullLiteral, AST::CharLiteral,
       AST::FormatString, AST::FormatTextPart
    nil
  end
end

#check_fatal_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 843

def check_fatal_call(arguments, scopes:)
  raise_sema_error("fatal does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("fatal expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  message_type = infer_expression(arguments.first.value, scopes:, expected_type: @ctx.types.fetch("str"))
  return @ctx.types.fetch("void") if string_like_type?(message_type)

  raise_sema_error("fatal expects str or cstr, got #{message_type}")
end

#check_field_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 901

def check_field_of_call(arguments, scopes:)
  raise_sema_error("field_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("field_of expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  evaluate_field_of_call(arguments, scopes:)
  builtin_field_handle_type
end

#check_for_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1048

def check_for_stmt(statement, scopes:, return_type:, allow_return:)
  if statement.threaded
    check_threaded_for_stmt(statement, scopes:, return_type:, allow_return:)
    return
  end

  statement.iterables.each do |iterable|
    validate_consuming_foreign_expression!(iterable, scopes:, root_allowed: false)
  end

  raise_sema_error("for loop binder count must match iterable count") unless statement.bindings.length == statement.iterables.length

  binding_infos = if statement.parallel?
                    check_parallel_for_bindings(statement, scopes:)
                  else
                    iterable_type = nil
                    loop_type = if range_expr?(statement.iterable)
                                  check_range_expr_loop(statement.iterable, scopes:)
                                else
                                  iterable_type = infer_expression(statement.iterable, scopes:)
                                  collection_loop_type(iterable_type) || iterator_loop_type(iterable_type)
                                end

                    raise_sema_error("for loop expects start..stop, array[T, N], span[T], or an iterable with iter()/next()") unless loop_type

                    binding_type = if iterable_type
                                     collection_loop_binding_type(iterable_type, loop_type) || loop_type
                                   else
                                     loop_type
                                   end
                    [{ binding: statement.binding, type: binding_type }]
                  end

  with_nested_scope(scopes) do |loop_scopes|
    binding_infos.each do |entry|
      binding = entry[:binding]
      ensure_non_reserved_primitive_name!(binding.name, kind_label: "for binding", line: binding.line, column: binding.column)
      current_actual_scope(loop_scopes)[binding.name] = value_binding(
        name: binding.name,
        type: entry[:type],
        mutable: false,
        kind: :let,
        id: @preassigned_local_binding_ids[binding.object_id],
      )
      record_declaration_binding(binding, current_actual_scope(loop_scopes)[binding.name])
    end
    with_loop do
      check_block(statement.body, scopes: loop_scopes, return_type:, allow_return:)
    end
  end
end

#check_format_string_literal(format_string, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1485

def check_format_string_literal(format_string, scopes:)
  format_string.parts.each do |part|
    next unless part.is_a?(AST::FormatExprPart)

    value_type = infer_expression(part.expression, scopes:)

    if part.format_spec
      case part.format_spec[:kind]
      when :precision
        unless value_type.is_a?(Types::Primitive) && value_type.float?
          raise_sema_error("format spec ':.N' is only valid for float and double, got #{value_type}")
        end
      when :hex
        unless format_string_integer_base_spec_supported?(value_type)
          raise_sema_error("format spec ':x' and ':X' are only valid for integer primitives and integer-backed enums/flags, got #{value_type}")
        end
      when :oct
        unless format_string_integer_base_spec_supported?(value_type)
          raise_sema_error("format spec ':o' and ':O' are only valid for integer primitives and integer-backed enums/flags, got #{value_type}")
        end
      when :bin
        unless format_string_integer_base_spec_supported?(value_type)
          raise_sema_error("format spec ':b' and ':B' are only valid for integer primitives and integer-backed enums/flags, got #{value_type}")
        end
      else
        raise_sema_error("unsupported format spec #{part.format_spec.inspect}")
      end
    else
      next if format_string_interpolation_supported?(value_type, context: "formatted string interpolation of #{value_type}")
      raise_sema_error("formatted string interpolation supports str, cstr, bool, numeric primitives, integer-backed enums/flags, and types implementing format_len()/append_format(output: ref[std.string.String]), got #{value_type}")
    end
  end
end

#check_function(binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 614

def check_function(binding)
  @local_completion_frames = @local_completion_frames.dup if @local_completion_frames.frozen?

  previous_type_substitutions = @current_type_substitutions
  previous_specialization_owner = @current_specialization_owner
  started_check = false
  return if binding.external
  return if @checked_function_bindings[binding.object_id]
  return if @checking_function_bindings[binding.object_id]

  @checking_function_bindings[binding.object_id] = true
  started_check = true
  @current_type_substitutions = binding.type_substitutions
  @current_specialization_owner = binding.specialization_owner
  with_error_node(binding.ast) do
    with_scope(binding.body_params) do |scopes|
      start_local_completion_frame(binding, scopes)
      if binding.type_params.any?
        if binding.ast.respond_to?(:body)
          check_generic_method_immutable_this(binding, scopes)
          check_generic_method_names(binding, scopes)
        end
        return
      end

      if binding.ast.is_a?(AST::ForeignFunctionDecl)
        record_callable_value_expression_site(binding.ast.mapping) unless binding.ast.mapping.is_a?(AST::Call)
        expression = foreign_mapping_expression(binding.ast)
        actual_type = with_foreign_mapping_context do
          infer_expression(expression, scopes:, expected_type: binding.type.return_type)
        end
        unless types_compatible?(actual_type, binding.type.return_type, expression:) || foreign_identity_projection_compatible?(actual_type, binding.type.return_type)
          raise_sema_error("foreign mapping #{binding.name} expects #{binding.type.return_type}, got #{actual_type}")
        end
      else
        validate_async_function_body!(binding.ast.body) if binding.async
        preassign_local_binding_ids(binding.ast.body)
        run_nullability_pre_pass(binding, scopes)
        if binding.ast.respond_to?(:const) && binding.ast.const
          with_compile_time do
            if binding.async
              with_async_function do
                check_block(binding.ast.body, scopes:, return_type: binding.body_return_type)
              end
            else
              check_block(binding.ast.body, scopes:, return_type: binding.type.return_type)
            end
          end
        elsif binding.async
          with_async_function do
            check_block(binding.ast.body, scopes:, return_type: binding.body_return_type)
          end
        else
          check_block(binding.ast.body, scopes:, return_type: binding.type.return_type)
        end
        check_definite_assignment(binding)
      end
    end
  end
ensure
  return unless started_check

  @checked_function_bindings[binding.object_id] = true
  finish_local_completion_frame(binding)
  @preassigned_local_binding_ids = {}
  @nullability_flow_result = nil
  @current_type_substitutions = previous_type_substitutions
  @current_specialization_owner = previous_specialization_owner
  @checking_function_bindings.delete(binding.object_id)
end

#check_function_call(binding, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 785

def check_function_call(binding, arguments, scopes:)
  arguments = canonicalize_call_arguments(arguments, binding.type.params, binding.name, binding)
  fill_positional_defaults!(arguments, binding)

  expected_params = binding.type.params
  required_count = count_required_params(binding)
  variadic = binding.type.is_a?(Types::Function) && binding.type.variadic
  unless variadic ? arguments.length >= required_count : arguments.length <= expected_params.length && arguments.length >= required_count
    raise_sema_error(arity_error_message(binding.type, binding.name, arguments.length, required_count:))
  end

  expected_params.each_with_index do |parameter, index|
    argument = arguments.fetch(index)
    actual_type = foreign_argument_actual_type(parameter, argument, scopes:, function_name: binding.name, expected_type: parameter.type)
    record_mutating_argument_identifier(argument, parameter)
    if foreign_cstr_boundary_parameter?(parameter)
      unless foreign_cstr_argument_compatible?(actual_type, parameter, expression: foreign_argument_expression(argument))
        raise_sema_error("argument #{parameter.name} to #{binding.name} expects #{parameter.type}, got #{actual_type}")
      end
    else
      unless call_argument_compatible?(actual_type, parameter.type, scopes:, external: binding.external, expression: foreign_argument_expression(argument))
        suggestion = explicit_cast_suggestion(actual_type, parameter.type)
        raise_sema_error("argument #{parameter.name} to #{binding.name} expects #{parameter.type}, got #{actual_type}", suggestion:)
      end
    end
  end

  arguments.drop(expected_params.length).each do |argument|
    infer_expression(argument.value, scopes:)
  end
end

#check_functions ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 252

def check_functions
  @ctx.top_level_functions.each_value do |binding|
    check_function(binding)
  end

  @ctx.methods.each_value do |method_map|
    method_map.each_value do |binding|
      check_function(binding)
    end
  end
end

#check_functions_collecting(errors) ⇒ Object

Per-function error collection used by check_collecting_errors. Continues past individual function failures, accumulating SemanticErrors.



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 282

def check_functions_collecting(errors)
  @ctx.top_level_functions.each_value do |binding|
    next if @checked_function_bindings[binding.object_id]

    prev_count = @structural_errors.length
    begin
      check_function(binding)
    rescue SemanticError => e
      errors << e
    end
    errors.concat(@structural_errors[prev_count..].to_a)
  end

  @ctx.methods.each_value do |method_map|
    method_map.each_value do |binding|
      next if @checked_function_bindings[binding.object_id]

      prev_count = @structural_errors.length
      begin
        check_function(binding)
      rescue SemanticError => e
        errors << e
      end
      errors.concat(@structural_errors[prev_count..].to_a)
    end
  end
end

#check_gather_stmt(statement, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1187

def check_gather_stmt(statement, scopes:)
  raise_sema_error("gather requires at least one handle", line: statement.line, column: statement.column) if statement.handles.empty?

  statement.handles.each do |handle|
    handle_type = infer_expression(handle, scopes:)
    raise_sema_error("gather expects Handle, got #{handle_type}", line: statement.line, column: statement.column) unless handle_type.is_a?(Types::Handle)
  end
end

#check_generic_method_immutable_this(binding, scopes) ⇒ Object

Scans generic method bodies for assignments to this through a non-editable receiver. Full body checking is deferred to call-site specialization, but immutable-this violations are type-independent.



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 601

def check_generic_method_immutable_this(binding, scopes)
  this_binding = scopes.first&.values&.find { |v| v.name == "this" }
  return unless this_binding
  return if this_binding.mutable

  binding.ast.body&.each do |statement|
    next unless statement.is_a?(AST::Assignment) && statement.operator == "="
    next unless statement.target.is_a?(AST::MemberAccess) && statement.target.receiver.is_a?(AST::Identifier) && statement.target.receiver.name == "this"

    raise_sema_error("cannot assign through immutable this", statement.target)
  end
end

#check_generic_method_names(binding, scopes) ⇒ Object

Verifies that every bare identifier used as a value expression inside a generic method body resolves to a known name (parameter, local, top-level value, function, type, import, or type parameter). This catches misspelled variables and undeclared names without touching any type-dependent logic, so it is safe to run during structural analysis before concrete types are substituted.



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 330

def check_generic_method_names(binding, scopes)
  names = Set.new
  binding.ast.body&.each do |statement|
    check_stmt_names(statement, scopes, binding, names)
  end
end

#check_generic_name(name, scopes, binding, node, names) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 453

def check_generic_name(name, scopes, binding, node, names)
  return if name == "_" || name == "this"
  return if names.include?(name)
  return if BUILTIN_CALLABLE_NAMES.include?(name)
  return if lookup_value(name, scopes)
  return if @ctx.top_level_functions.key?(name)
  return if @ctx.types.key?(name)
  return if @ctx.imports.key?(name)
  return if binding.type_params.include?(name)

  raise_sema_error("unknown name #{name}", node)
end

#check_get_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 852

def check_get_call(arguments, scopes:)
  raise_sema_error("get does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("get expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  source_expr = arguments.first.value
  index_expr = arguments[1].value
  source_type = infer_expression(source_expr, scopes:)
  index_type = infer_expression(index_expr, scopes:)
  raise_sema_error("get index must be an integer type, got #{index_type}") unless integer_type?(index_type)

  if array_type?(source_type)
    raise_sema_error("get requires an addressable array value") unless addressable_storage_expression?(source_expr, scopes:)

    Types::Registry.nullable(pointer_to(array_element_type(source_type)))
  elsif source_type.is_a?(Types::Span)
    Types::Registry.nullable(pointer_to(source_type.element_type))
  else
    raise_sema_error("get expects an array or span, got #{source_type}")
  end
end

#check_has_attribute_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 915

def check_has_attribute_call(arguments, scopes:)
  raise_sema_error("has_attribute does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("has_attribute expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  target = resolve_reflection_target_argument(arguments.first.value, scopes:)
  binding = resolve_attribute_name_argument(arguments[1].value)
  validate_attribute_target_compatibility!(target, binding)

  @ctx.types.fetch("bool")
end

#check_hash_call(resolution, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 426

def check_hash_call(resolution, arguments, scopes:)
  raise_sema_error("hash does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("hash expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  validate_hash_operation_argument!(arguments.first.value, resolution.target_type, scopes:, operation: "hash")
  @ctx.types.fetch("uint")
end

#check_inline_for_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1275

def check_inline_for_stmt(statement, scopes:, return_type:, allow_return:)
  iterable = evaluate_compile_time_const_value(statement.iterables.first, scopes:)
  raise_sema_error("inline for iterable must be a compile-time constant") unless iterable.is_a?(Array)
  raise_sema_error("inline for iterable is empty") if iterable.empty?

  loop_var_name = statement.bindings.first.name
  ensure_non_reserved_primitive_name!(loop_var_name, kind_label: "for binding", line: statement.bindings.first.line, column: statement.bindings.first.column)

  # The loop is unrolled at compile time, so check the body once per element:
  # each iteration's element type is validated and any per-element
  # specialization (e.g. `equal[field.type]` for a struct field, or a
  # `format_value[field.type]` recursion) is discovered by sema rather than
  # first appearing during lowering.
  iterable.each do |element|
    with_nested_scope(scopes) do |loop_scopes|
      current_actual_scope(loop_scopes)[loop_var_name] = value_binding(
        name: loop_var_name,
        type: inline_for_element_type(element),
        mutable: false,
        kind: :let,
        id: @preassigned_local_binding_ids[statement.bindings.first.object_id],
        const_value: element,
      )
      with_loop do
        with_compile_time do
          check_block(statement.body, scopes: loop_scopes, return_type:, allow_return:)
        end
      end
    end
  end
end

#check_inline_if_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1334

def check_inline_if_stmt(statement, scopes:, return_type:, allow_return:)
  chosen_branch = statement.branches.find do |branch|
    condition_value = evaluate_compile_time_const_value(branch.condition, scopes:)
    raise_sema_error("inline if condition must be a compile-time constant") if condition_value.nil?
    raise_sema_error("inline if condition must be bool") unless condition_value == true || condition_value == false
    condition_value
  end

  if chosen_branch
    with_compile_time do
      check_block(chosen_branch.body, scopes:, return_type:, allow_return:)
    end
  elsif statement.else_body
    with_compile_time do
      check_block(statement.else_body, scopes:, return_type:, allow_return:)
    end
  end
end

#check_inline_match_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1353

def check_inline_match_stmt(statement, scopes:, return_type:, allow_return:)
  scrutinee = evaluate_compile_time_const_value(statement.expression, scopes:)
  raise_sema_error("inline match scrutinee must be a compile-time constant") if scrutinee.nil?

  chosen_arm = statement.arms.find do |arm|
    pattern_value = evaluate_compile_time_const_value(arm.pattern, scopes:)
    scrutinee == pattern_value
  end

  if chosen_arm
    with_compile_time do
      check_block(chosen_arm.body, scopes:, return_type:, allow_return:)
    end
  end
end

#check_inline_while_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1323

def check_inline_while_stmt(statement, scopes:, return_type:, allow_return:)
  condition = evaluate_compile_time_const_value(statement.condition, scopes:)
  raise_sema_error("inline while condition must be a compile-time constant") if condition.nil?

  with_loop do
    with_compile_time do
      check_block(statement.body, scopes:, return_type:, allow_return:)
    end
  end
end

#check_integer_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 755

def check_integer_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  each_integer_match_arm(statement, scrutinee_type, scopes:) do |arm|
    check_block(arm.body, scopes:, return_type:, allow_return:)
  end
end

#check_interface_conformance!(receiver_type, interface) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/interface_conformance.rb', line 30

def check_interface_conformance!(receiver_type, interface)
  interface.methods.each_value do |interface_method|
    method = lookup_local_method_for_interface(receiver_type, interface_method.name)
    raise_sema_error("type #{receiver_type} implements interface #{interface.name} but is missing method #{interface_method.name}") unless method

    check_interface_method_match!(receiver_type, interface, interface_method, method)
  end
end

#check_interface_conformances ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/interface_conformance.rb', line 6

def check_interface_conformances
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      next unless decl.is_a?(AST::StructDecl) || decl.is_a?(AST::OpaqueDecl)
      next if decl.implements.empty?

      receiver_type = @ctx.types.fetch(decl.name)
      resolved_interfaces = []
      seen = {}

      decl.implements.each do |interface_ref|
        interface = resolve_interface_ref(interface_ref)
        raise_sema_error("duplicate interface #{decl.name} implements #{interface.name}") if seen.key?(interface)

        seen[interface] = true
        resolved_interfaces << interface
        check_interface_conformance!(receiver_type, interface)
      end

      @ctx.implemented_interfaces[interface_implementation_key(receiver_type)] = resolved_interfaces.freeze
    end
  end
end

#check_interface_method_match!(receiver_type, interface, interface_method, method) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/interface_conformance.rb', line 50

def check_interface_method_match!(receiver_type, interface, interface_method, method)
  if method.ast.is_a?(AST::MethodDef) && method.ast.type_params.any?
    raise_sema_error("type #{receiver_type} method #{method.name} does not satisfy interface #{interface.name}: interface methods cannot be implemented by generic methods")
  end

  if interface_method.kind == :static
    raise_sema_error("type #{receiver_type} method #{method.name} does not satisfy interface #{interface.name}: method kind does not match") unless method.type.receiver_type.nil?
  else
    raise_sema_error("type #{receiver_type} method #{method.name} does not satisfy interface #{interface.name}: method kind does not match") if method.type.receiver_type.nil?

    expected_editable = interface_method.kind == :editable
    actual_editable = method.type.receiver_editable
    if actual_editable != expected_editable
      raise_sema_error("type #{receiver_type} method #{method.name} does not satisfy interface #{interface.name}: receiver editability does not match")
    end
  end

  method_params = method.type.params.map(&:type)
  interface_params = interface_method.params.map(&:type)
  unless method_params == interface_params && method.type.return_type == interface_method.return_type && method.async == interface_method.async
    raise_sema_error("type #{receiver_type} method #{method.name} does not satisfy interface #{interface.name}: signature does not match")
  end
end

#check_layout_type_via_ct(type_ref, context:, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 591

def check_layout_type_via_ct(type_ref, context:, scopes:)
  return false unless scopes && type_ref.name.parts.length >= 1

  first_part = type_ref.name.parts.first
  binding = lookup_value(first_part, scopes)
  return false unless binding && !binding.const_value.nil?

  expression = AST.build_chain_from_parts(type_ref.name.parts)
  return false unless expression

  ct_value = evaluate_compile_time_const_value(expression, scopes:)
  if ct_value.is_a?(Types::Struct) || ct_value.is_a?(Types::Primitive) ||
     ct_value.is_a?(Types::Union) || ct_value.is_a?(Types::Nullable) ||
     ct_value.is_a?(Types::StructInstance)
    if sized_layout_type?(ct_value)
      return true
    end
  end

  false
end

#check_local_decl(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 223

def check_local_decl(statement, scopes:, return_type:, allow_return:)
  if statement.destructure_bindings
    check_local_decl_destructure(statement, scopes:, return_type:, allow_return:)
    return
  end

  current_scope = current_actual_scope(scopes)
  discard_binding = statement.name == "_" || let_else_discard_binding_syntax?(statement)
  raise_sema_error("duplicate local #{statement.name}") if !discard_binding && current_scope.key?(statement.name)
  ensure_non_reserved_primitive_name!(statement.name, kind_label: "local", line: statement.line, column: statement.column) unless discard_binding

  declared_type = statement.type ? resolve_type_ref(statement.type) : nil
  if statement.value
    validate_consuming_foreign_expression!(statement.value, scopes:, root_allowed: false)
    inferred_type = infer_expression(statement.value, scopes:, expected_type: declared_type)
  else
    raise_sema_error("local #{statement.name} without initializer requires an explicit type") unless declared_type

    begin
      zero_initializable_type?(declared_type)
    rescue SemanticError
      raise_sema_error("local #{statement.name} without initializer requires a zero-initializable type, got #{declared_type}")
    end

    inferred_type = declared_type
  end

  storage_type, final_type, const_value =
    if statement.else_body || statement.recovered_else
      check_local_decl_let_else(statement, scopes:, return_type:, allow_return:, discard_binding:, declared_type:, inferred_type:)
    else
      check_local_decl_plain(statement, scopes:, discard_binding:, declared_type:, inferred_type:)
    end

  if noncopyable_event_storage_type?(final_type) && !fresh_noncopyable_event_initializer?(statement.value, final_type, scopes:)
    raise_sema_error("local #{statement.name} cannot copy event storage type #{final_type}")
  end

  unless discard_binding
    current_scope[statement.name] = value_binding(
      name: statement.name,
      type: storage_type,
      mutable: statement.kind == :var,
      kind: statement.kind,
      flow_type: final_type,
      const_value:,
      id: @preassigned_local_binding_ids[statement.object_id],
    )
    record_declaration_binding(statement, current_scope[statement.name])
  end
end

#check_local_decl_destructure(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 275

def check_local_decl_destructure(statement, scopes:, return_type:, allow_return:)
  value_type = infer_expression(statement.value, scopes:)

  if statement.destructure_type_name
    check_local_decl_struct_destructure(statement, value_type, scopes:)
  elsif value_type.is_a?(Types::Tuple)
    check_local_decl_tuple_destructure(statement, value_type, scopes:)
  else
    raise_sema_error("destructure requires a tuple or struct, got #{value_type}")
  end
end

#check_local_decl_let_else(statement, scopes:, return_type:, allow_return:, discard_binding:, declared_type:, inferred_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 368

def check_local_decl_let_else(statement, scopes:, return_type:, allow_return:,
                                discard_binding:, declared_type:, inferred_type:)
  success_type = let_else_success_type(inferred_type)
  error_type = let_else_error_type(inferred_type)

  if statement.recovered_else
    success_type ||= declared_type || @error_type
    error_type ||= @error_type if statement.else_binding
  else
    raise_sema_error("let-else initializer for #{statement.name} must be nullable, Option[T], or Result[T, E], got #{inferred_type}") unless success_type
  end

  if discard_binding && declared_type
    raise_sema_error("let-else discard binding _ cannot have a type annotation")
  end

  if discard_binding && statement.kind == :var
    raise_sema_error("var-else discard binding _ is not allowed")
  end

  if statement.else_binding && !error_type
    raise_sema_error("let-else error binding for #{statement.name} requires Result[T, E], got #{inferred_type}")
  end

  if declared_type && let_else_source_type?(declared_type)
    raise_sema_error("let-else type annotation for #{statement.name} must be the success type, got #{declared_type}")
  end

  if declared_type
    validate_local_ref_type!(declared_type, statement.name)
    validate_local_proc_type!(declared_type, statement.name, initializer: statement.value)
    ensure_assignable!(
      success_type, declared_type,
      "cannot assign #{success_type} to #{statement.name}: expected #{declared_type}",
      expression: statement.value, scopes:,
      contextual_int_to_float: contextual_int_to_float_target?(declared_type),
      line: statement.line, column: statement.column,
    )
    final_type = declared_type
  else
    raise_sema_error("cannot bind void result to #{statement.name}") if success_type.void? && !discard_binding
    final_type = success_type
  end

  unless discard_binding
    validate_local_ref_type!(final_type, statement.name)
    validate_local_proc_type!(final_type, statement.name, initializer: statement.value)
  end

  else_scopes = scopes
  if statement.else_binding
    ensure_non_reserved_primitive_name!(statement.else_binding.name, kind_label: "let-else error binding", line: statement.else_binding.line, column: statement.else_binding.column)
    else_binding = value_binding(
      name: statement.else_binding.name, type: error_type, mutable: false, kind: :let,
      id: preassigned_local_binding_id_for(statement.else_binding),
    )
    record_declaration_binding(statement.else_binding, else_binding)
    else_scopes = scopes + [{ statement.else_binding.name => else_binding }]
  end

  check_block(statement.else_body, scopes: else_scopes, return_type:, allow_return:) if statement.else_body
  if statement.else_body && !statement.recovered_else
    terminator = if inside_loop?
                   ControlFlow::Termination.block_always_terminates_in_loop?(statement.else_body)
                 else
                   cfg_block_always_terminates?(statement.else_body)
                 end
    unless terminator
      raise_sema_error("else block for #{statement.name} must exit control flow at line #{statement.line}")
    end
  end

  storage_type = statement.kind == :var ? final_type : inferred_type
  [storage_type, final_type, nil]
end

#check_local_decl_plain(statement, scopes:, discard_binding:, declared_type:, inferred_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 444

def check_local_decl_plain(statement, scopes:, discard_binding:, declared_type:, inferred_type:)
  if declared_type
    validate_local_ref_type!(declared_type, statement.name)
    validate_local_proc_type!(declared_type, statement.name, initializer: statement.value)
    ensure_assignable!(
      inferred_type, declared_type,
      "cannot assign #{inferred_type} to #{statement.name}: expected #{declared_type}",
      expression: statement.value, scopes:,
      contextual_int_to_float: contextual_int_to_float_target?(declared_type),
      line: statement.line, column: statement.column,
    )
    final_type = declared_type
  else
    raise_sema_error("cannot infer type for #{statement.name} from null") if inferred_type.is_a?(Types::Null)
    raise_sema_error("cannot bind void result to #{statement.name}") if inferred_type.void?
    final_type = inferred_type
  end

  validate_local_ref_type!(final_type, statement.name)
  validate_local_proc_type!(final_type, statement.name, initializer: statement.value)

  const_value = statement.kind == :let && statement.value ? evaluate_compile_time_const_value(statement.value, scopes:) : nil
  [final_type, final_type, const_value]
end

#check_local_decl_struct_destructure(statement, value_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 307

def check_local_decl_struct_destructure(statement, value_type, scopes:)
  type_name = statement.destructure_type_name
  struct_type = if type_name.is_a?(Array)
                  resolve_qualified_type_name(type_name)
                else
                  @ctx.types[type_name]
                end
  display_name = type_name.is_a?(Array) ? type_name.join(".") : type_name
  raise_sema_error("unknown type #{display_name} for struct destructure") unless struct_type
  if struct_type.is_a?(Types::GenericStructDefinition)
    if value_type.is_a?(Types::StructInstance) && value_type.definition == struct_type
      fields = value_type.fields
    else
      raise_sema_error("generic type #{display_name} requires type arguments")
    end
  else
    raise_sema_error("#{display_name} is not a struct") unless struct_type.is_a?(Types::Struct) || struct_type.is_a?(Types::Tuple)
    ensure_assignable!(value_type, struct_type, "cannot destructure #{value_type} as #{display_name}")
    fields = struct_type.fields
  end
  raise_sema_error("destructure pattern has #{statement.destructure_bindings.length} bindings but #{display_name} has #{fields.length} fields") unless statement.destructure_bindings.length == fields.length

  current_scope = current_actual_scope(scopes)
  statement.destructure_bindings.each do |name|
    next if name == "_"
    raise_sema_error("duplicate local #{name} in destructure") if current_scope.key?(name)
    raise_sema_error("unknown field #{display_name}.#{name}") unless fields.key?(name)
    ensure_non_reserved_primitive_name!(name, kind_label: "local", line: statement.line, column: statement.column)
    field_type = fields[name]
    current_scope[name] = value_binding(
      name:,
      type: field_type,
      mutable: false,
      kind: :let,
      id: @preassigned_local_binding_ids[statement.object_id],
    )
    record_declaration_binding(statement, current_scope[name])
  end
end

#check_local_decl_tuple_destructure(statement, value_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 287

def check_local_decl_tuple_destructure(statement, value_type, scopes:)
  raise_sema_error("destructure pattern has #{statement.destructure_bindings.length} bindings but tuple has #{value_type.element_types.length} elements") unless statement.destructure_bindings.length == value_type.element_types.length

  current_scope = current_actual_scope(scopes)
  statement.destructure_bindings.each_with_index do |name, index|
    next if name == "_"
    raise_sema_error("duplicate local #{name} in destructure") if current_scope.key?(name)
    ensure_non_reserved_primitive_name!(name, kind_label: "local", line: statement.line, column: statement.column)
    field_type = value_type.element_types[index]
    current_scope[name] = value_binding(
      name:,
      type: field_type,
      mutable: false,
      kind: :let,
      id: @preassigned_local_binding_ids[statement.object_id],
    )
    record_declaration_binding(statement, current_scope[name])
  end
end

#check_match_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 564

def check_match_stmt(statement, scopes:, return_type:, allow_return:)
  validate_consuming_foreign_expression!(statement.expression, scopes:, root_allowed: false)
  scrutinee_type = infer_expression(statement.expression, scopes:)
  if error_type?(scrutinee_type)
    check_recovered_match_stmt(statement, scopes:, return_type:, allow_return:)
  elsif scrutinee_type.is_a?(Types::Enum)
    check_enum_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  elsif scrutinee_type.is_a?(Types::Variant)
    check_variant_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  elsif integer_type?(scrutinee_type)
    check_integer_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  elsif scrutinee_type.is_a?(Types::StringView)
    check_string_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  elsif scrutinee_type.is_a?(Types::Tuple)
    check_tuple_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  else
    raise_sema_error("match requires an enum, variant, or integer scrutinee, got #{scrutinee_type}")
  end
end

#check_order_call(resolution, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 445

def check_order_call(resolution, arguments, scopes:)
  raise_sema_error("order does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("order expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  arguments.each do |argument|
    validate_hash_operation_argument!(argument.value, resolution.target_type, scopes:, operation: "order")
  end

  @ctx.types.fetch("int")
end

#check_parallel_block_stmt(statement, scopes:, return_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1177

def check_parallel_block_stmt(statement, scopes:, return_type:)
  @uses_parallel_for = true
  raise_sema_error("parallel block must contain at least two statements", line: statement.line, column: statement.column) if statement.bodies.length < 2

  statement.bodies.each do |body|
    validate_threaded_for_body!(body)
    check_block(body, scopes:, return_type:, allow_return: false)
  end
end

#check_parallel_for_bindings(statement, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1100

def check_parallel_for_bindings(statement, scopes:)
  raise_sema_error("parallel for loops currently support arrays and spans only") if statement.iterables.any? { |iterable| range_expr?(iterable) }

  iterable_types = statement.iterables.map { |iterable| infer_expression(iterable, scopes:) }
  binding_infos = iterable_types.each_with_index.map do |iterable_type, index|
    loop_type = collection_loop_type(iterable_type)
    raise_sema_error("parallel for loops expect arrays or spans for each iterable") unless loop_type

    binding_type = collection_loop_binding_type(iterable_type, loop_type) || loop_type
    { binding: statement.bindings[index], iterable_type:, type: binding_type }
  end

  ensure_parallel_for_static_lengths_match!(binding_infos.map { |entry| entry[:iterable_type] })
  binding_infos
end

#check_ptr_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 891

def check_ptr_of_call(arguments, scopes:)
  raise_sema_error("ptr_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("ptr_of expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  source_expression = arguments.first.value
  source_type = infer_expression(source_expression, scopes:)
  return pointer_to(referenced_type(source_type)) if ref_type?(source_type)

  pointer_to(infer_addr_source_type(source_expression, scopes:))
end

#check_range_expr_loop(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1218

def check_range_expr_loop(expression, scopes:)
  start_type = infer_expression(expression.start_expr, scopes:)
  stop_type = infer_expression(expression.end_expr, scopes:)

  unless integer_type?(start_type) && integer_type?(stop_type)
    raise_sema_error("range bounds must be integer types, got #{start_type} and #{stop_type}")
  end

  if start_type != stop_type
    if expression.start_expr.is_a?(AST::IntegerLiteral)
      start_type = infer_expression(expression.start_expr, scopes:, expected_type: stop_type)
    elsif expression.end_expr.is_a?(AST::IntegerLiteral)
      stop_type = infer_expression(expression.end_expr, scopes:, expected_type: start_type)
    end
  end

  raise_sema_error("range bounds must use matching integer types, got #{start_type} and #{stop_type}") unless start_type == stop_type

  start_type
end

#check_range_index_assignment(statement, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 526

def check_range_index_assignment(statement, scopes:)
  target = statement.target
  range = target.index

  raise_sema_error("range index assignment requires an expression list on the right-hand side") unless statement.value.is_a?(AST::ExpressionList)
  raise_sema_error("range index assignment requires integer literal bounds") unless range.start_expr.is_a?(AST::IntegerLiteral) && range.end_expr.is_a?(AST::IntegerLiteral)

  start_val = range.start_expr.value
  end_val = range.end_expr.value
  raise_sema_error("range start must be less than end in range index assignment") unless start_val < end_val

  count = end_val - start_val
  raise_sema_error("range index assignment: range [#{start_val}..#{end_val}) spans #{count} elements but tuple has #{statement.value.elements.length}") unless statement.value.elements.length == count

  receiver_type = infer_lvalue_receiver(
    target.receiver,
    scopes:,
    allow_pointer_identifier: true,
    require_mutable_pointer: true,
    allow_span_param_identifier: true,
  )
  element_type = infer_index_result_type(receiver_type, @ctx.types.fetch("ptr_uint"))

  statement.value.elements.each_with_index do |elem, i|
    elem = elem.is_a?(AST::Argument) ? elem.value : elem
    validate_consuming_foreign_expression!(elem, scopes:, root_allowed: false)
    elem_type = infer_expression(elem, scopes:, expected_type: element_type)
    ensure_assignable!(
      elem_type,
      element_type,
      "range index assignment element #{i}: cannot assign #{elem_type} to #{element_type}",
      expression: elem,
      contextual_int_to_float: contextual_int_to_float_target?(element_type),
      line: statement.line,
    )
  end
end

#check_read_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 886

def check_read_call(arguments, scopes:)
  validate_read_call_arguments!(arguments)

  infer_reference_value_type(arguments.first.value, scopes:)
end

#check_recovered_match_arm_body(arm, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 919

def check_recovered_match_arm_body(arm, scopes:, return_type:, allow_return:)
  arm_scopes = scopes.dup
  if arm.binding_name
    ensure_non_reserved_primitive_name!(arm.binding_name, kind_label: "match binding", line: arm.binding_line, column: arm.binding_column)
    binding = value_binding(
      name: arm.binding_name,
      type: @error_type,
      mutable: true,
      kind: :local,
      id: @preassigned_local_binding_ids.fetch(arm.object_id),
    )
    arm_scopes = arm_scopes + [{ arm.binding_name => binding }]
    record_declaration_binding(arm, binding)
  end
  check_block(arm.body, scopes: arm_scopes, return_type:, allow_return:)
end

#check_recovered_match_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 913

def check_recovered_match_stmt(statement, scopes:, return_type:, allow_return:)
  statement.arms.each do |arm|
    check_recovered_match_arm_body(arm, scopes:, return_type:, allow_return:)
  end
end

#check_ref_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 872

def check_ref_of_call(arguments, scopes:)
  raise_sema_error("ref_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("ref_of expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  source_type = infer_addr_source_type(arguments.first.value, scopes:)
  Types::Registry.generic_instance("ref", [source_type])
end

#check_reinterpret_call(target_type, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 211

def check_reinterpret_call(target_type, arguments, scopes:)
  raise_sema_error("reinterpret requires exactly one argument") unless arguments.length == 1
  raise_sema_error("reinterpret does not support named arguments") if arguments.first.name
  require_unsafe!("reinterpret requires unsafe")

  source_type = infer_expression(arguments.first.value, scopes:)
  unless reinterpretable_type?(source_type) && reinterpretable_type?(target_type)
    raise_sema_error("reinterpret requires non-array concrete sized types, got #{source_type} -> #{target_type}")
  end

  source_size = CompileTime::Layout.size_of(source_type)
  target_size = CompileTime::Layout.size_of(target_type)
  if source_size && target_size && source_size != target_size
    raise_sema_error("reinterpret requires equal-size types, got #{source_type} (#{source_size} byte#{source_size == 1 ? '' : 's'}) -> #{target_type} (#{target_size} byte#{target_size == 1 ? '' : 's'})")
  end

  target_type
end

#check_simd_construction(simd_type, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 54

def check_simd_construction(simd_type, arguments, scopes:)
  raise_sema_error("simd construction requires exactly #{simd_type.lane_count} positional arguments, got #{arguments.length}") unless arguments.length == simd_type.lane_count
  raise_sema_error("simd construction does not accept named arguments") if arguments.any?(&:name)

  element_type = simd_type.element_type
  arguments.each do |argument|
    actual_type = infer_expression(argument.value, scopes:, expected_type: element_type)
    ensure_assignable!(
      actual_type,
      element_type,
      "simd lane expects #{element_type}, got #{actual_type}",
      expression: argument.value,
      contextual_int_to_float: contextual_int_to_float_target?(element_type),
    )
  end
  simd_type
end

#check_simd_method_call(kind, receiver_type, _receiver, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 603

def check_simd_method_call(kind, receiver_type, _receiver, arguments, scopes:)
  raise_sema_error("simd methods do not support named arguments") if arguments.any?(&:name)

  case kind
  when :simd_lane_with
    raise_sema_error("with expects exactly 2 arguments, got #{arguments.length}") unless arguments.length == 2

    index_arg = arguments[0].value
    index_type = infer_expression(index_arg, scopes:)
    raise_sema_error("with index must be an integer, got #{index_type}") unless index_type.integer?

    value_type = infer_expression(arguments[1].value, scopes:, expected_type: receiver_type.element_type)
    ensure_assignable!(
      value_type,
      receiver_type.element_type,
      "with expects lane value of type #{receiver_type.element_type}, got #{value_type}",
    )
    receiver_type
  end
end

#check_stack_escape_call(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1386

def check_stack_escape_call(expression, scopes:)
  callee = expression.callee
  return unless callee.is_a?(AST::Identifier)
  return unless %w[ptr_of ref_of const_ptr_of].include?(callee.name)
  return if expression.arguments.empty?

  arg = expression.arguments.first
  source = arg.respond_to?(:value) ? arg.value : arg
  check_stack_local_source(source, scopes:, builtin: callee.name)
end

#check_stack_local_source(expression, scopes:, builtin:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1397

def check_stack_local_source(expression, scopes:, builtin:)
  case expression
  when AST::Identifier
    binding = lookup_local_binding(expression.name, scopes)
    return unless binding
    return unless %i[let var param].include?(binding.kind)
    return if stack_safe_pointer_source?(binding)
    raise_sema_error(
      "#{builtin}(#{expression.name}) cannot be returned: pointer to function-local storage",
      expression,
    )
  when AST::MemberAccess
    check_stack_local_source(expression.receiver, scopes:, builtin:)
  when AST::IndexAccess
    check_stack_local_source(expression.receiver, scopes:, builtin:)
  end
end

#check_stack_pointer_escape_in_return(expression, scopes:) ⇒ Object

Walks the returned expression tree to detect ptr_of/ref_of/const_ptr_of applied to a stack-local variable whose address must not escape the function. Only flags when the pointer value itself (not a computed result through a function call) reaches the return.



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1373

def check_stack_pointer_escape_in_return(expression, scopes:)
  return unless expression

  if expression.is_a?(AST::Call)
    check_stack_escape_call(expression, scopes:)
  elsif expression.is_a?(AST::BinaryOp)
    check_stack_pointer_escape_in_return(expression.left, scopes:)
    check_stack_pointer_escape_in_return(expression.right, scopes:)
  elsif expression.is_a?(AST::UnaryOp)
    check_stack_pointer_escape_in_return(expression.operand, scopes:)
  end
end

#check_statement(statement, scopes:, return_type:, allow_return: true) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 59

def check_statement(statement, scopes:, return_type:, allow_return: true)
  with_error_node(statement) do
    case statement
    when AST::ErrorBlockStmt
      if statement.header_type == :unsafe
        @unsafe_statement_lines << statement.line
        begin
          with_unsafe do
            check_block(statement.body, scopes:, return_type:, allow_return:)
          end
        ensure
          @unsafe_statement_lines.pop
        end
      elsif statement.header_type == :if && statement.header_expression
        validate_consuming_foreign_expression!(statement.header_expression, scopes:, root_allowed: false)
        condition_type = infer_expression(statement.header_expression, scopes:, expected_type: @ctx.types.fetch("bool"))
        ensure_assignable!(condition_type, @ctx.types.fetch("bool"), "if condition must be bool, got #{condition_type}", expression: statement.header_expression, line: statement.line, column: statement.column)
        true_refinements = flow_refinements(statement.header_expression, truthy: true, scopes:)
        check_block(statement.body, scopes: scopes_with_refinements(scopes, true_refinements), return_type:, allow_return:)
        return flow_refinements(statement.header_expression, truthy: false, scopes:) if cfg_block_always_terminates?(statement.body)
      elsif statement.header_type == :while && statement.header_expression
        validate_consuming_foreign_expression!(statement.header_expression, scopes:, root_allowed: false)
        condition_type = infer_expression(statement.header_expression, scopes:, expected_type: @ctx.types.fetch("bool"))
        ensure_assignable!(condition_type, @ctx.types.fetch("bool"), "while condition must be bool, got #{condition_type}", expression: statement.header_expression, line: statement.line, column: statement.column)
        with_loop do
          body_scopes = scopes_with_refinements(scopes, flow_refinements(statement.header_expression, truthy: true, scopes:))
          check_block(statement.body, scopes: body_scopes, return_type:, allow_return:)
        end
      elsif statement.header_type == :for
        if statement.header_bindings && statement.header_iterables
          check_for_stmt(recovered_for_statement(statement), scopes:, return_type:, allow_return:)
        else
          with_loop do
            check_block(statement.body, scopes:, return_type:, allow_return:)
          end
        end
      else
        check_block(statement.body, scopes:, return_type:, allow_return:)
      end
    when AST::LocalDecl
      check_local_decl(statement, scopes:, return_type:, allow_return:)
    when AST::ErrorStmt
      nil
    when AST::Assignment
      check_assignment(statement, scopes:)
    when AST::IfStmt
      if statement.inline
        check_inline_if_stmt(statement, scopes:, return_type:, allow_return:)
        next
      end

      false_refinements = {}
      branch_bodies_terminate = []
      statement.branches.each do |branch|
        branch_scopes = scopes_with_refinements(scopes, false_refinements)
        if branch.condition.is_a?(AST::ErrorExpr)
          check_block(branch.body, scopes: branch_scopes, return_type:, allow_return:)
          branch_bodies_terminate << cfg_block_always_terminates?(branch.body)
          next
        end

        validate_consuming_foreign_expression!(branch.condition, scopes: branch_scopes, root_allowed: false)
        condition_type = infer_expression(branch.condition, scopes: branch_scopes, expected_type: @ctx.types.fetch("bool"))
        ensure_assignable!(condition_type, @ctx.types.fetch("bool"), "if condition must be bool, got #{condition_type}", expression: branch.condition, line: branch.line, column: branch.column)
        true_refinements = merge_refinements(false_refinements, flow_refinements(branch.condition, truthy: true, scopes: branch_scopes))
        check_block(branch.body, scopes: scopes_with_refinements(scopes, true_refinements), return_type:, allow_return:)
        branch_bodies_terminate << cfg_block_always_terminates?(branch.body)
        false_refinements = merge_refinements(false_refinements, flow_refinements(branch.condition, truthy: false, scopes: branch_scopes))
      end
      check_block(statement.else_body, scopes: scopes_with_refinements(scopes, false_refinements), return_type:, allow_return:) if statement.else_body
      return false_refinements if statement.else_body.nil? && branch_bodies_terminate.all?
    when AST::MatchStmt
      if statement.inline
        check_inline_match_stmt(statement, scopes:, return_type:, allow_return:)
      else
        check_match_stmt(statement, scopes:, return_type:, allow_return:)
      end
    when AST::UnsafeStmt
      @unsafe_statement_lines << statement.line
      begin
        with_unsafe do
          check_block(statement.body, scopes:, return_type:, allow_return:)
        end
      ensure
        @unsafe_statement_lines.pop
      end
    when AST::StaticAssert
      check_static_assert(statement, scopes:)
    when AST::EmitStmt
      check_emit_stmt(statement)
    when AST::ForStmt
      if statement.inline
        check_inline_for_stmt(statement, scopes:, return_type:, allow_return:)
      else
        check_for_stmt(statement, scopes:, return_type:, allow_return:)
      end
    when AST::ParallelBlockStmt
      check_parallel_block_stmt(statement, scopes:, return_type:)
    when AST::GatherStmt
      check_gather_stmt(statement, scopes:)
    when AST::WhileStmt
      if statement.inline
        check_inline_while_stmt(statement, scopes:, return_type:, allow_return:)
      elsif statement.condition.is_a?(AST::ErrorExpr)
        with_loop do
          check_block(statement.body, scopes:, return_type:, allow_return:)
        end
      else
        validate_consuming_foreign_expression!(statement.condition, scopes:, root_allowed: false)
        condition_type = infer_expression(statement.condition, scopes:, expected_type: @ctx.types.fetch("bool"))
        ensure_assignable!(condition_type, @ctx.types.fetch("bool"), "while condition must be bool, got #{condition_type}", expression: statement.condition, line: statement.line, column: statement.column)
        with_loop do
          body_scopes = scopes_with_refinements(scopes, flow_refinements(statement.condition, truthy: true, scopes:))
          check_block(statement.body, scopes: body_scopes, return_type:, allow_return:)
        end
      end
    when AST::PassStmt
      nil
    when AST::BreakStmt
      raise_sema_error("break must be inside a loop") unless inside_loop?
    when AST::ContinueStmt
      raise_sema_error("continue must be inside a loop") unless inside_loop?
    when AST::ReturnStmt
      raise_sema_error("return is not allowed inside defer blocks") unless allow_return

      validate_consuming_foreign_expression!(statement.value, scopes:, root_allowed: false) if statement.value
      value_type = statement.value ? infer_expression(statement.value, scopes:, expected_type: return_type) : @ctx.types.fetch("void")
      check_stack_pointer_escape_in_return(statement.value, scopes:) if statement.value
      ensure_assignable!(
        value_type,
        return_type,
        "return type mismatch: expected #{return_type}, got #{value_type}",
        expression: statement.value,
        contextual_int_to_float: contextual_int_to_float_target?(return_type),
        line: statement.line,
      )
    when AST::DeferStmt
      if statement.body
        with_loop_barrier do
          check_block(statement.body, scopes:, return_type:, allow_return: false)
        end
      else
        validate_consuming_foreign_expression!(statement.expression, scopes:, root_allowed: true)
        validate_hoistable_foreign_expression!(statement.expression, scopes:, root_hoistable: false)
        infer_expression(statement.expression, scopes:)
      end
    when AST::ExpressionStmt
      validate_consuming_foreign_expression!(statement.expression, scopes:, root_allowed: true)
      if statement.expression.is_a?(AST::UnaryOp) && statement.expression.operator == "?"
        infer_propagate_expression(statement.expression.operand, scopes:, allow_void_success: true)
      else
        infer_expression(statement.expression, scopes:)
      end
      return consuming_foreign_call_refinements(statement.expression, scopes:)
    when AST::WhenStmt
      check_when_stmt(statement, scopes:, return_type:, allow_return:)
    else
      raise_sema_error("unsupported statement #{statement.class.name}")
    end

    nil
  end
end

#check_static_assert(statement, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1197

def check_static_assert(statement, scopes:)
  validate_consuming_foreign_expression!(statement.condition, scopes:, root_allowed: false)
  validate_consuming_foreign_expression!(statement.message, scopes:, root_allowed: false)
  validate_hoistable_foreign_expression!(statement.condition, scopes:, root_hoistable: false)
  validate_hoistable_foreign_expression!(statement.message, scopes:, root_hoistable: false)
  condition_type = infer_expression(statement.condition, scopes:, expected_type: @ctx.types.fetch("bool"))
  ensure_assignable!(condition_type, @ctx.types.fetch("bool"), "static_assert condition must be bool, got #{condition_type}")
  condition_value = evaluate_compile_time_const_value(statement.condition, scopes:)
  raise_sema_error("static_assert condition must be a compile-time bool constant") unless condition_value == true || condition_value == false
  raise_sema_error("static_assert message must be a string literal") unless statement.message.is_a?(AST::StringLiteral)

  message_type = infer_expression(statement.message, scopes:, expected_type: @ctx.types.fetch("str"))
  return if string_like_type?(message_type)

  raise_sema_error("static_assert message must be str or cstr, got #{message_type}")
end

#check_stmt_names(stmt, scopes, binding, names) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 337

def check_stmt_names(stmt, scopes, binding, names)
  case stmt
  when AST::LocalDecl
    check_expr_names(stmt.value, scopes, binding, names) if stmt.value
    names.add(stmt.name) if stmt.name
    try_record_generic_local_snapshot(stmt, scopes, binding) if stmt.name && stmt.value
  when AST::Assignment
    check_expr_names(stmt.target, scopes, binding, names)
    check_expr_names(stmt.value, scopes, binding, names)
  when AST::ExpressionStmt
    check_expr_names(stmt.expression, scopes, binding, names)
  when AST::ReturnStmt
    check_expr_names(stmt.value, scopes, binding, names) if stmt.value
  when AST::IfStmt
    stmt.branches.each do |b|
      check_expr_names(b.condition, scopes, binding, names)
      branch_names = names.dup
      b.body&.each { |s| check_stmt_names(s, scopes, binding, branch_names) }
    end
    else_names = names.dup
    stmt.else_body&.each { |s| check_stmt_names(s, scopes, binding, else_names) }
  when AST::WhileStmt
    check_expr_names(stmt.condition, scopes, binding, names)
    body_names = names.dup
    stmt.body&.each { |s| check_stmt_names(s, scopes, binding, body_names) }
  when AST::ForStmt
    Array(stmt.iterables).each { |i| check_expr_names(i, scopes, binding, names) }
    body_names = names.dup
    Array(stmt.bindings).each { |b| body_names.add(b.respond_to?(:name) ? b.name : b) }
    stmt.body&.each { |s| check_stmt_names(s, scopes, binding, body_names) }
  when AST::MatchStmt
    check_expr_names(stmt.expression, scopes, binding, names)
    stmt.arms.each do |arm|
      arm_names = names.dup
      arm_names.add(arm.binding_name) if arm.binding_name
      arm.body&.each { |s| check_stmt_names(s, scopes, binding, arm_names) }
    end
  when AST::UnsafeStmt, AST::ParallelBlockStmt
    body_names = names.dup
    stmt.body&.each { |s| check_stmt_names(s, scopes, binding, body_names) }
  when AST::DeferStmt
    check_expr_names(stmt.expression, scopes, binding, names) if stmt.expression
    body_names = names.dup
    stmt.body&.each { |s| check_stmt_names(s, scopes, binding, body_names) }
  when AST::WhenStmt
    check_expr_names(stmt.discriminant, scopes, binding, names)
    stmt.branches.each do |b|
      branch_names = names.dup
      b.body&.each { |s| check_stmt_names(s, scopes, binding, branch_names) }
    end
    else_names = names.dup
    stmt.else_body&.each { |s| check_stmt_names(s, scopes, binding, else_names) }
  when AST::ErrorBlockStmt
    body_names = names.dup
    stmt.body&.each { |s| check_stmt_names(s, scopes, binding, body_names) }
  when AST::BreakStmt, AST::ContinueStmt, AST::PassStmt, AST::StaticAssert, AST::EmitStmt
    nil
  end
end

#check_str_buffer_method_call(kind, receiver, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 466

def check_str_buffer_method_call(kind, receiver, arguments, scopes:)
  method_name = str_buffer_method_name(kind)
  receiver_type = infer_expression(receiver, scopes:)
  raise_sema_error("unknown method #{receiver_type}.#{method_name}") unless str_buffer_type?(receiver_type)

  case kind
  when :str_buffer_clear, :str_buffer_len, :str_buffer_capacity, :str_buffer_as_str, :str_buffer_as_cstr
    raise_sema_error("#{method_name} does not support named arguments") if arguments.any?(&:name)
    raise_sema_error("#{method_name} expects 0 arguments, got #{arguments.length}") unless arguments.empty?
  when :str_buffer_assign, :str_buffer_append, :str_buffer_assign_format, :str_buffer_append_format
    raise_sema_error("#{method_name} does not support named arguments") if arguments.any?(&:name)
    raise_sema_error("#{method_name} expects 1 argument, got #{arguments.length}") unless arguments.length == 1
  else
    raise_sema_error("unsupported str_buffer method #{kind}")
  end

  case kind
  when :str_buffer_clear
    record_editable_receiver_expression(receiver)
    raise_sema_error("cannot call editable method #{receiver_type}.clear on an immutable receiver") unless assignable_receiver?(receiver, scopes)

    @ctx.types.fetch("void")
  when :str_buffer_assign, :str_buffer_append, :str_buffer_assign_format, :str_buffer_append_format
    record_editable_receiver_expression(receiver)
    raise_sema_error("cannot call editable method #{receiver_type}.#{method_name} on an immutable receiver") unless assignable_receiver?(receiver, scopes)

    actual_type = infer_expression(arguments.first.value, scopes:, expected_type: @ctx.types.fetch("str"))
    ensure_argument_assignable!(
      actual_type,
      @ctx.types.fetch("str"),
      external: false,
      message: "argument value to #{receiver_type}.#{method_name} expects str, got #{actual_type}",
      expression: arguments.first.value,
    )

    @ctx.types.fetch("void")
  when :str_buffer_len, :str_buffer_capacity
    @ctx.types.fetch("ptr_uint")
  when :str_buffer_as_str
    raise_sema_error("#{receiver_type}.as_str requires a safe stored receiver") unless safe_reference_source_expression?(receiver, scopes:)

    @ctx.types.fetch("str")
  when :str_buffer_as_cstr
    raise_sema_error("#{receiver_type}.as_cstr requires a safe stored receiver") unless safe_reference_source_expression?(receiver, scopes:)

    @ctx.types.fetch("cstr")
  else
    raise_sema_error("unsupported str_buffer method #{kind}")
  end
end

#check_string_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 761

def check_string_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  each_string_match_arm(statement, scrutinee_type, scopes:) do |arm|
    check_block(arm.body, scopes:, return_type:, allow_return:)
  end
end

#check_struct_match_pattern(arguments, arm_name, scrutinee_type, arm_scopes, scopes:, arm:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 964

def check_struct_match_pattern(arguments, arm_name, scrutinee_type, arm_scopes, scopes:, arm:)
  payload_fields = scrutinee_type.arm(arm_name)
  raise_sema_error("variant arm #{scrutinee_type}.#{arm_name} has no payload fields for struct pattern") if payload_fields.nil? || payload_fields.empty?

  # Nested struct detection: if arm has exactly one field whose type is a struct,
  # auto-destructure through to the struct's own fields, but only when none of
  # the arguments reference the arm's own field name directly.
  if payload_fields.size == 1
    native_field = payload_fields.keys.first
    has_native_reference = arguments.any? do |arg|
      next false if !arg.name && arg.value.is_a?(AST::Identifier) && arg.value.name == "_"
      name = arg.name || (arg.value.is_a?(AST::Identifier) ? arg.value.name : nil)
      name == native_field
    end
    unless has_native_reference
      single_field_type = payload_fields.values.first
      payload_fields = single_field_type.fields if single_field_type.is_a?(Types::Struct)
    end
  end

  has_guards = false
  seen_fields = {}
  equality_cover = {}

  arguments.each do |arg|
    if arg.value.is_a?(AST::Identifier) && arg.value.name == "_"
      # _ discard: skip this field, no binding, no guard
      next
    elsif arg.name
      # Equality pattern: kind = Kind.boss
      field_name = arg.name
      raise_sema_error("unknown field #{scrutinee_type}.#{arm_name}.#{field_name}") unless payload_fields.key?(field_name)
      raise_sema_error("duplicate field #{field_name} in struct pattern") if seen_fields.key?(field_name)
      seen_fields[field_name] = true
      has_guards = true

      field_type = payload_fields[field_name]
      actual_type = infer_expression(arg.value, scopes:, expected_type: field_type)
      ensure_assignable!(actual_type, field_type, "field #{field_name} expects #{field_type}, got #{actual_type}", expression: arg.value)

      if field_type.is_a?(Types::Enum) && arg.value.is_a?(AST::MemberAccess)
        equality_cover[field_name] = [] unless equality_cover.key?(field_name)
        equality_cover[field_name] << arg.value.member
      end
    elsif arg.value.is_a?(AST::Identifier)
      # Binding: position
      field_name = arg.value.name
      raise_sema_error("unknown field #{scrutinee_type}.#{arm_name}.#{field_name}") unless payload_fields.key?(field_name)
      raise_sema_error("duplicate field #{field_name} in struct pattern") if seen_fields.key?(field_name)
      seen_fields[field_name] = true

      field_type = payload_fields[field_name]
      binding = value_binding(
        name: field_name,
        type: field_type,
        mutable: false,
        kind: :local,
        id: @preassigned_local_binding_ids[arg.object_id],
      )
      arm_scopes.last[field_name] = binding
    elsif arg.value.is_a?(AST::BinaryOp) && arg.value.left.is_a?(AST::Identifier)
      # Guard: hp > 0
      field_name = arg.value.left.name
      raise_sema_error("unknown field #{scrutinee_type}.#{arm_name}.#{field_name}") unless payload_fields.key?(field_name)
      raise_sema_error("duplicate field #{field_name} in struct pattern") if seen_fields.key?(field_name)
      seen_fields[field_name] = true
      has_guards = true

      field_type = payload_fields[field_name]
      comparison_operators = ["==", "!=", "<", "<=", ">", ">="]
      unless comparison_operators.include?(arg.value.operator)
        raise_sema_error("unsupported guard operator '#{arg.value.operator}' in struct pattern; use ==, !=, <, <=, >, or >=", arg.value)
      end

      operand_type = infer_expression(arg.value.right, scopes:, expected_type: field_type)
      ensure_assignable!(operand_type, field_type, "guard comparison expects #{field_type}, got #{operand_type}", expression: arg.value.right)
    else
      raise_sema_error("invalid field pattern in struct match arm; expected field name, comparison, or equality", expression: arg.value)
    end
  end

  [has_guards, equality_cover]
end

#check_struct_with_call(struct_type, _receiver_expression, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 72

def check_struct_with_call(struct_type, _receiver_expression, arguments, scopes:)
  check_aggregate_field_arguments(struct_type, arguments, scopes:, context: "struct.with()")
  struct_type
end

#check_threaded_for_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1123

def check_threaded_for_stmt(statement, scopes:, return_type:, allow_return:)
  @uses_parallel_for = true
  raise_sema_error("parallel for requires a range expression (start..end)") unless range_expr?(statement.iterable)

  loop_type = check_range_expr_loop(statement.iterable, scopes:)
  validate_threaded_for_body!(statement.body)

  with_nested_scope(scopes) do |loop_scopes|
    binding = statement.binding
    ensure_non_reserved_primitive_name!(binding.name, kind_label: "for binding", line: binding.line, column: binding.column)
    current_actual_scope(loop_scopes)[binding.name] = value_binding(
      name: binding.name,
      type: loop_type,
      mutable: false,
      kind: :let,
      id: @preassigned_local_binding_ids[binding.object_id],
    )
    record_declaration_binding(binding, current_actual_scope(loop_scopes)[binding.name])
    check_block(statement.body, scopes: loop_scopes, return_type:, allow_return: false)
  end
end

#check_top_level_static_asserts ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 628

def check_top_level_static_asserts
  expanded_declarations.grep(AST::StaticAssert).each do |statement|
    check_static_assert(statement, scopes: [])
  end
end

#check_top_level_values ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 6

def check_top_level_values
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      case decl
      when AST::ConstDecl
        begin
          if decl.block_body
            check_block_body_const(decl)
          else
            check_expr_const(decl)
          end
        rescue SemanticError => e
          collect_structural_error(e)
        end
      when AST::VarDecl
        binding = @ctx.top_level_values.fetch(decl.name)
        if decl.value
          validate_consuming_foreign_expression!(decl.value, scopes: [], root_allowed: false)
          validate_hoistable_foreign_expression!(decl.value, scopes: [], root_hoistable: false)
          actual_type = infer_expression(decl.value, scopes: [], expected_type: binding.type)
          ensure_assignable!(
            actual_type,
            binding.type,
            "cannot assign #{actual_type} to module variable #{decl.name}: expected #{binding.type}",
            expression: decl.value,
          )
          validate_static_storage_initializer!(decl.value, scopes: [])
        else
          zero_initializable_type?(binding.type)
        end
      end
    end
  end
end

#check_tuple_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 767

def check_tuple_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  each_tuple_match_arm(statement, scrutinee_type, scopes:) do |arm|
    check_block(arm.body, scopes:, return_type:, allow_return:)
  end
end

#check_variant_arm_construction(callable, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 102

def check_variant_arm_construction(callable, arguments, scopes:)
  variant_type, arm_name = callable
  fields = variant_type.arm(arm_name)

  if fields.nil? || fields.empty?
    raise_sema_error("variant arm #{variant_type}.#{arm_name} has no payload; construct it without arguments") unless arguments.empty?

    return variant_type
  end

  raise_sema_error("variant arm construction requires named arguments") unless arguments.all?(&:name)

  provided = {}
  arguments.each do |argument|
    field_type = fields[argument.name]
    raise_sema_error("unknown field #{variant_type}.#{arm_name}.#{argument.name}") unless field_type
    raise_sema_error("duplicate field #{variant_type}.#{arm_name}.#{argument.name}") if provided.key?(argument.name)

    actual_type = infer_expression(argument.value, scopes:, expected_type: field_type)
    ensure_assignable!(
      actual_type,
      field_type,
      "field #{variant_type}.#{arm_name}.#{argument.name} expects #{field_type}, got #{actual_type}",
      expression: argument.value,
      contextual_int_to_float: contextual_int_to_float_target?(field_type),
    )
    provided[argument.name] = true
  end

  missing = fields.keys - provided.keys
  missing.reject! { |name| fields[name].void? }
  raise_sema_error("variant arm #{variant_type}.#{arm_name} is missing fields: #{missing.join(', ')}") unless missing.empty?

  variant_type
end

#check_variant_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 819

def check_variant_match_stmt(statement, scrutinee_type, scopes:, return_type:, allow_return:)
  each_variant_match_arm(statement, scrutinee_type, scopes:) do |arm, arm_scopes|
    check_block(arm.body, scopes: arm_scopes, return_type:, allow_return:)
  end
end

#check_when_stmt(statement, scopes:, return_type:, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1251

def check_when_stmt(statement, scopes:, return_type:, allow_return:)
  discriminant_value = evaluate_when_discriminant(statement.discriminant)

  chosen_branch = statement.branches.find do |branch|
    pattern_value = evaluate_compile_time_const_value(branch.pattern, scopes:)
    discriminant_value == pattern_value
  end

  if chosen_branch
    check_block(chosen_branch.body, scopes:, return_type:, allow_return:)
  elsif statement.else_body
    check_block(statement.else_body, scopes:, return_type:, allow_return:)
  else
    raise_sema_error("when discriminant value #{discriminant_value} does not match any branch and no else is provided")
  end
end

#check_zero_call(target_type, arguments, expected_type: nil, operation: "zero") ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 230

def check_zero_call(target_type, arguments, expected_type: nil, operation: "zero")
  raise_sema_error("#{operation} expects 0 arguments, got #{arguments.length}") unless arguments.empty?

  zero_initializable_type?(target_type, operation:)
  if expected_type.is_a?(Types::Nullable) && typed_null_target_type?(expected_type.base) && types_compatible?(target_type, expected_type.base)
    raise_sema_error("use null instead of #{operation}[#{target_type}] in nullable pointer-like context #{expected_type}")
  end

  target_type
end

#collect_emit_declarations ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 212

def collect_emit_declarations
  collect_emit_from_declarations(expanded_declarations)
  @ctx.ast.declarations.grep(AST::ConstDecl).each { |decl| @ctx.const_declarations[decl.name] ||= decl }
end

#collect_emit_from_declarations(declarations) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 217

def collect_emit_from_declarations(declarations)
  declarations.each do |decl|
    case decl
    when AST::FunctionDef
      next unless decl.const && decl.body

      collect_emit_from_statements(decl.body)
    when AST::WhenStmt
      body = when_chosen_body(decl)
      collect_emit_from_declarations(body) if body
    when AST::StructDecl, AST::ExtendingBlock
      # no emit in structs/extending blocks
    end
  end
end

#collect_emit_from_node(node) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 255

def collect_emit_from_node(node)
  case node
  when AST::FunctionDef
    node.body&.each do |stmt|
      if stmt.is_a?(AST::EmitStmt)
        nested = stmt.declaration
        next if nested.is_a?(AST::ErrorExpr)

        @ctx.ast.declarations << nested
        collect_emit_from_node(nested)
      end
    end
  end
end

#collect_emit_from_statements(statements) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 233

def collect_emit_from_statements(statements)
  statements.each do |stmt|
    case stmt
    when AST::EmitStmt
      emit_decl = stmt.declaration
      next if emit_decl.is_a?(AST::ErrorExpr)

      @ctx.ast.declarations << emit_decl
      collect_emit_from_node(emit_decl)
    when AST::WhenStmt
      body = when_chosen_body(stmt) || []
      body.each { |nested| collect_emit_from_statements([nested]) }
    when AST::ForStmt, AST::WhileStmt, AST::IfStmt, AST::MatchStmt
      next unless stmt.inline
      stmt.body&.each { |s| collect_emit_from_statements([s]) }
      if stmt.is_a?(AST::IfStmt)
        stmt.else_body&.each { |s| collect_emit_from_statements([s]) }
      end
    end
  end
end

#collect_structural_error(error) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 329

def collect_structural_error(error)
  raise error unless @collecting_errors

  @structural_errors << error
end

#collect_type_substitutions(pattern_type, actual_type, substitutions, function_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 286

def collect_type_substitutions(pattern_type, actual_type, substitutions, function_name)
  case pattern_type
  when Types::TypeVar
    existing = substitutions[pattern_type.name]
    if existing && existing != actual_type
      raise_sema_error("conflicting type argument #{pattern_type.name} for function #{function_name}: got #{existing} and #{actual_type}")
    end

    substitutions[pattern_type.name] ||= actual_type
  when Types::Nullable
    candidate = actual_type.is_a?(Types::Nullable) ? actual_type.base : actual_type
    collect_type_substitutions(pattern_type.base, candidate, substitutions, function_name)
  when Types::GenericInstance
    if ref_type?(pattern_type) && !ref_type?(actual_type)
      collect_type_substitutions(referenced_type(pattern_type), actual_type, substitutions, function_name)
      return
    end

    if own_type?(actual_type) && (mutable_pointer_type?(pattern_type) || const_pointer_type?(pattern_type))
      collect_type_substitutions(pointee_type(pattern_type), owned_referent_type(actual_type), substitutions, function_name)
      return
    end

    return unless actual_type.is_a?(Types::GenericInstance)
    return unless actual_type.name == pattern_type.name && actual_type.arguments.length == pattern_type.arguments.length

    pattern_type.arguments.zip(actual_type.arguments).each do |expected_argument, actual_argument|
      next if expected_argument.is_a?(Types::LiteralTypeArg)

      collect_type_substitutions(expected_argument, actual_argument, substitutions, function_name)
    end
  when Types::VariantInstance
    return unless actual_type.is_a?(Types::VariantInstance)
    return unless actual_type.definition == pattern_type.definition || (actual_type.name == pattern_type.name && actual_type.arguments.length == pattern_type.arguments.length)

    pattern_type.arguments.zip(actual_type.arguments).each do |expected_argument, actual_argument|
      next if expected_argument.is_a?(Types::LiteralTypeArg)

      collect_type_substitutions(expected_argument, actual_argument, substitutions, function_name)
    end
  when Types::Span
    return unless actual_type.is_a?(Types::Span)

    collect_type_substitutions(pattern_type.element_type, actual_type.element_type, substitutions, function_name)
  when Types::Task
    return unless actual_type.is_a?(Types::Task)

    collect_type_substitutions(pattern_type.result_type, actual_type.result_type, substitutions, function_name)
  when Types::Proc
    if task_root_proc_type?(pattern_type) && actual_type.is_a?(Types::Task)
      collect_type_substitutions(pattern_type.return_type, actual_type, substitutions, function_name)
      return
    end

    actual_params = case actual_type
    when Types::Proc
      return unless actual_type.params.length == pattern_type.params.length

      actual_type.params
    when Types::Function
      return if actual_type.receiver_type || actual_type.variadic
      return unless actual_type.params.length == pattern_type.params.length

      actual_type.params
    else
      return
    end

    pattern_type.params.zip(actual_params).each do |expected_param, actual_param|
      collect_type_substitutions(expected_param.type, actual_param.type, substitutions, function_name)
    end
    collect_type_substitutions(pattern_type.return_type, actual_type.return_type, substitutions, function_name)
  when Types::StructInstance
    return unless actual_type.is_a?(Types::StructInstance)
    return unless actual_type.definition == pattern_type.definition && actual_type.arguments.length == pattern_type.arguments.length

    pattern_type.arguments.zip(actual_type.arguments).each do |expected_argument, actual_argument|
      collect_type_substitutions(expected_argument, actual_argument, substitutions, function_name)
    end
  when Types::Function
    return unless actual_type.is_a?(Types::Function)
    return unless actual_type.params.length == pattern_type.params.length

    pattern_type.params.zip(actual_type.params).each do |expected_param, actual_param|
      collect_type_substitutions(expected_param.type, actual_param.type, substitutions, function_name)
    end
    collect_type_substitutions(pattern_type.return_type, actual_type.return_type, substitutions, function_name)
  end
end

#collection_loop_binding_type(iterable_type, element_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 868

def collection_loop_binding_type(iterable_type, element_type)
  super
end

#collection_loop_ref_element_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 872

def collection_loop_ref_element_type?(type)
  super
end

#collection_loop_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 864

def collection_loop_type(type)
  super
end

#common_integer_type(left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 183

def common_integer_type(left_type, right_type)
  left_type = left_type.backing_type if left_type.is_a?(Types::EnumBase)
  right_type = right_type.backing_type if right_type.is_a?(Types::EnumBase)
  return unless left_type.is_a?(Types::Primitive) && right_type.is_a?(Types::Primitive)
  return unless left_type.integer? && right_type.integer?
  return left_type if left_type == right_type
  return unless left_type.fixed_width_integer? && right_type.fixed_width_integer?
  return unless left_type.signed_integer? == right_type.signed_integer?

  left_type.integer_width >= right_type.integer_width ? left_type : right_type
end

#common_numeric_type(left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 167

def common_numeric_type(left_type, right_type)
  left_type = left_type.backing_type if left_type.is_a?(Types::EnumBase)
  right_type = right_type.backing_type if right_type.is_a?(Types::EnumBase)
  return unless left_type.is_a?(Types::Primitive) && right_type.is_a?(Types::Primitive)
  return unless left_type.numeric? && right_type.numeric?
  return left_type if left_type == right_type

  return common_integer_type(left_type, right_type) if left_type.integer? && right_type.integer?
  return wider_float_type(left_type, right_type) if left_type.float? && right_type.float?

  float_type, integer_type = left_type.float? ? [left_type, right_type] : [right_type, left_type]
  return unless integer_type.integer? && integer_type.fixed_width_integer?

  float_type
end

#conditional_common_type(then_type, else_type, then_expression:, else_expression:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 307

def conditional_common_type(then_type, else_type, then_expression:, else_expression:)
  return then_type if then_type == else_type

  numeric_type = common_numeric_type(then_type, else_type)
  return numeric_type if numeric_type

  if (nullable_type = conditional_null_common_type(then_type, else_type))
    return nullable_type
  end

  if (nullable_type = conditional_null_common_type(else_type, then_type))
    return nullable_type
  end

  return then_type if types_compatible?(else_type, then_type, expression: else_expression)
  return else_type if types_compatible?(then_type, else_type, expression: then_expression)

  nil
end

#conditional_null_common_type(null_type, other_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 333

def conditional_null_common_type(null_type, other_type)
  return unless null_type.is_a?(Types::Null)

  if other_type.is_a?(Types::Nullable)
    return other_type if null_type.target_type.nil? || null_type.target_type == other_type.base

    return nil
  end

  return unless nullable_candidate?(other_type)
  return if null_type.target_type && null_type.target_type != other_type

  Types::Registry.nullable(other_type)
end

#consuming_foreign_call_refinements(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1231

def consuming_foreign_call_refinements(expression, scopes:)
  foreign_call = resolve_foreign_call_expression(expression, scopes:)
  return {} unless foreign_call

  binding = foreign_call[:binding]
  return {} unless foreign_call_consumes_binding?(binding)

  binding.type.params.each_with_index.each_with_object({}) do |(parameter, index), refinements|
    next unless parameter.passing_mode == :consuming

    argument = foreign_call[:call].arguments.fetch(index)
    argument_binding = foreign_consuming_argument_binding(parameter, argument, scopes:, function_name: binding.name)
    refinements[argument.value.name] = @null_type if argument_binding.storage_type.is_a?(Types::Nullable)
  end
end

#contains_callable_ref_type?(type, visited = {}) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1141

def contains_callable_ref_type?(type, visited = {})
  visitor = ContainsCallableRefTypeVisitor.new
  visitor.visit(type)
  visitor.found?
end

#contains_proc_type?(type, visited = {}) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1147

def contains_proc_type?(type, visited = {})
  visitor = ContainsProcTypeVisitor.new
  visitor.visit(type)
  visitor.found?
end

#contains_type_var?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 798

def contains_type_var?(type)
  super
end

#contextual_int_to_float_fits?(expression, expected_type, scopes) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 150

def contextual_int_to_float_fits?(expression, expected_type, scopes)
  value = evaluate_compile_time_const_value(expression, scopes:)
  return true unless value.is_a?(Numeric)

  float_constant_fits_type?(value, expected_type)
end

#count_required_params(binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 1071

def count_required_params(binding)
  return binding.type.params.length unless binding.ast.params.any? { |p| p.respond_to?(:default_value) && p.default_value }

  seen_default = false
  binding.ast.params.count do |p|
    has_default = p.respond_to?(:default_value) && p.default_value
    seen_default = true if has_default
    !has_default && !seen_default
  end
end

#current_actual_scope(scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 6

def current_actual_scope(scopes)
  scopes.reverse_each do |scope|
    return scope unless scope.is_a?(FlowScope)
  end

  raise_sema_error("missing lexical scope")
end

#current_error_node ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 499

def current_error_node
  @error_node_stack.reverse_each.find { |node| !node.nil? }
end

#current_return_context ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 105

def current_return_context
  @return_context_stack.last
end

#current_type_param_constraints ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 10

def current_type_param_constraints
  @current_type_param_constraints || {}
end

#current_type_params ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 6

def current_type_params
  @current_type_substitutions || {}
end

#declare_attributes ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 313

def declare_attributes
  expanded_declarations.grep(AST::AttributeDecl).each do |decl|
    with_error_node(decl) do
      raise_sema_error("duplicate attribute #{decl.name}") if @ctx.attributes.key?(decl.name)

      params = []
      seen = {}
      decl.params.each do |param|
        raise_sema_error("duplicate attribute parameter #{decl.name}.#{param.name}") if seen.key?(param.name)

        seen[param.name] = true
        params << Types::Registry.parameter(param.name, resolve_type_ref(param.type))
      end

      @ctx.attributes[decl.name] = AttributeBinding.new(
        name: decl.name,
        targets: decl.targets.freeze,
        params: params.freeze,
        module_name: @ctx.module_name,
        builtin: false,
        ast: decl,
      )
    end
  end
end

#declare_function_binding(decl, receiver_type: nil, declared_receiver_type: nil, receiver_type_param_names: [], receiver_type_param_constraints: {}, external: false) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 52

def declare_function_binding(decl, receiver_type: nil, declared_receiver_type: nil, receiver_type_param_names: [], receiver_type_param_constraints: {}, external: false)
  foreign = decl.is_a?(AST::ForeignFunctionDecl)
  async_function = decl.respond_to?(:async) ? decl.async : false
  if decl.is_a?(AST::MethodDef)
    ensure_non_reserved_primitive_name!(decl.name, kind_label: "function", line: decl.line, column: decl.column)
  end
  type_param_names = receiver_type_param_names + decl.type_params.map(&:name)
  type_param_constraints = receiver_type_param_constraints.merge(resolve_type_param_constraints(decl.type_params))
  raise_sema_error("external function #{decl.name} cannot be generic") if external && type_param_names.any?
  raise_sema_error("main cannot be generic") if decl.name == "main" && type_param_names.any?
  raise_sema_error("external function #{decl.name} cannot be async") if external && async_function
  raise_sema_error("foreign function #{decl.name} cannot be async") if foreign && async_function

  method_kind = decl.is_a?(AST::MethodDef) ? decl.kind : nil
  instance_method = receiver_type && method_kind != :static

  type_params = {}
  type_param_names.each do |name|
    raise_sema_error("duplicate type parameter #{decl.name}[#{name}]") if type_params.key?(name)

    type_params[name] = Types::TypeVar.new(name)
  end

  body_params = []
  if instance_method
    body_params << value_binding(
      name: "this",
      type: receiver_type,
      mutable: method_kind == :editable,
      kind: :param,
    )
  end

  public_params = []
  any_default = false
  decl.params.each do |param|
    begin
      ensure_non_reserved_primitive_name!(param.name, kind_label: "parameter", line: param.line || decl.line, column: param.column)
      type = resolve_type_ref(param.type, type_params:, type_param_constraints:)
      validate_parameter_ref_type!(type, function_name: decl.name, parameter_name: param.name, external:)
      reject_foreign_nullable_value_type!(type, function_name: decl.name, parameter_name: param.name) if foreign || external
      validate_parameter_proc_type!(type, function_name: decl.name, parameter_name: param.name, external:, foreign:)
      raise_sema_error("parameter #{param.name} of #{decl.name} must pass event storage through ref[...] or pointers, got #{type}") if noncopyable_event_storage_type?(type)

      has_default = param.respond_to?(:default_value) && param.default_value
      raise_sema_error("external function #{decl.name} cannot have default parameter values") if external && has_default
      raise_sema_error("foreign function #{decl.name} cannot have default parameter values") if foreign && has_default
      raise_sema_error("default parameter #{param.name} of #{decl.name} must appear after required parameters") if !has_default && any_default
      any_default = true if has_default

      if external && array_type?(type)
        raise_sema_error("external function #{decl.name} cannot take array parameters")
      end

      if param.is_a?(AST::ForeignParam)
        if external
          raise_sema_error("external parameter #{param.name} of #{decl.name} cannot use `as`") if param.boundary_type
          unless %i[plain out inout].include?(param.mode)
            raise_sema_error("external parameter #{param.name} of #{decl.name} cannot use `#{param.mode}`")
          end
        elsif foreign
          raise_sema_error("foreign parameter #{param.name} cannot use `as` with #{param.mode}") if ![:plain, :in].include?(param.mode) && param.boundary_type
          validate_consuming_foreign_parameter!(type, function_name: decl.name, parameter_name: param.name) if param.mode == :consuming
        end

        boundary_type = foreign_parameter_boundary_type(param, type, type_params:, type_param_constraints:)
        validate_foreign_boundary_type!(type, boundary_type, function_name: decl.name, parameter_name: param.name) if foreign && param.boundary_type && param.mode != :in
        validate_in_foreign_parameter!(type, boundary_type, function_name: decl.name, parameter_name: param.name) if foreign && param.mode == :in
        param_binding = value_binding(name: param.name, type: boundary_type || type, mutable: false, kind: :param)
        body_params << param_binding
        record_declaration_binding(param, param_binding)
        if foreign && param.boundary_type
          body_params << value_binding(
            name: foreign_mapping_public_alias_name(param.name),
            type:,
            mutable: false,
            kind: :param,
          )
        end
        public_params << Types::Registry.parameter(param.name, type, passing_mode: param.mode, boundary_type: boundary_type)
      else
        param_binding = value_binding(name: param.name, type:, mutable: false, kind: :param)
        body_params << param_binding
        record_declaration_binding(param, param_binding)
        public_params << Types::Registry.parameter(param.name, type) if external
      end
    rescue SemanticError => e
      collect_structural_error(e)
      param_binding = value_binding(name: param.name, type: @error_type, mutable: false, kind: :param)
      body_params << param_binding
    end
  end

  receiver_editable = false
  call_params = body_params
  function_receiver_type = nil
  if instance_method
    receiver_editable = method_kind == :editable
    call_params = body_params.drop(1)
    function_receiver_type = receiver_type
  end

  call_params = public_params if foreign || external

  seen = {}
  body_params.each do |param|
    raise_sema_error("duplicate parameter #{param.name} in #{decl.name}") if seen.key?(param.name)

    seen[param.name] = true
  end

  body_return_type = decl.return_type ? resolve_type_ref(decl.return_type, type_params:, type_param_constraints:) : @ctx.types.fetch("void")
  validate_return_ref_type!(body_return_type, function_name: decl.name)
  reject_foreign_nullable_value_type!(body_return_type, function_name: decl.name, parameter_name: nil) if foreign || external
  validate_return_proc_type!(body_return_type, function_name: decl.name)
  raise_sema_error("function #{decl.name} cannot return event storage type #{body_return_type}") if noncopyable_event_storage_type?(body_return_type)
  if decl.name == "main" && async_function && body_return_type != @ctx.types.fetch("int") && body_return_type != @ctx.types.fetch("void")
    raise_sema_error("async main must return int or void")
  end
  if foreign && public_params.any? { |param| param.passing_mode == :consuming } && body_return_type != @ctx.types.fetch("void")
    raise_sema_error("foreign function #{decl.name} with consuming parameters must return void")
  end
  if external && array_type?(body_return_type)
    raise_sema_error("external function #{decl.name} cannot return arrays")
  end
  function_return_type = async_function ? Types::Registry.task(body_return_type) : body_return_type

  function_type = Types::Registry.function(
    decl.name,
    params: (foreign || external) ? call_params : call_params.map { |param| Types::Registry.parameter(param.name, param.type) },
    return_type: function_return_type,
    receiver_type: function_receiver_type,
    receiver_editable:,
    variadic: decl.respond_to?(:variadic) ? decl.variadic : false,
    external:,
  )

  FunctionBinding.new(
    name: decl.name,
    type: function_type,
    body_params:,
    body_return_type: body_return_type,
    ast: decl,
    external:,
    async: async_function,
    type_params: type_param_names.freeze,
    type_param_constraints: type_param_constraints.freeze,
    instances: {},
    type_arguments: [].freeze,
    owner: self,
    specialization_owner: nil,
    type_substitutions: {}.freeze,
    declared_receiver_type: declared_receiver_type,
  )
end

#declare_functions ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 6

def declare_functions
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      case decl
      when AST::FunctionDef
        ensure_available_value_name!(decl.name, kind_label: "function", line: decl.line, column: decl.column)
        @ctx.top_level_functions[decl.name] = declare_function_binding(decl)
      when AST::ExternFunctionDecl
        ensure_available_value_name!(decl.name, kind_label: "function", line: decl.line, column: decl.column)
        if decl.mapping && !decl.mapping.is_a?(AST::StringLiteral)
          raise_sema_error("external function #{decl.name} mapping must be a c-string literal")
        end
        @ctx.top_level_functions[decl.name] = declare_function_binding(decl, external: true)
      when AST::ForeignFunctionDecl
        ensure_available_value_name!(decl.name, kind_label: "function", line: decl.line, column: decl.column)
        @ctx.top_level_functions[decl.name] = declare_function_binding(decl)
      when AST::ExtendingBlock
        dispatch_receiver_type, receiver_type, receiver_type_param_names, receiver_type_param_constraints = resolve_methods_receiver_target(decl.type_name)

        decl.methods.each do |method|
          begin
            binding = with_error_node(method) do
              declare_function_binding(
                method,
                receiver_type:,
                declared_receiver_type: receiver_type,
                receiver_type_param_names:,
                receiver_type_param_constraints:,
              )
            end
            instance_method = receiver_type && method.kind != :static
            method_key = instance_method ? binding.name : "static:#{binding.name}"
            raise_sema_error("duplicate method #{decl.type_name}.#{binding.name}") if @ctx.methods[dispatch_receiver_type].key?(method_key)

            @ctx.methods[dispatch_receiver_type][method_key] = binding
          rescue SemanticError => e
            collect_structural_error(e)
          end
        end
      end
    end
  rescue SemanticError => e
    collect_structural_error(e)
  end
end

#declare_interface_binding(decl) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 339

def declare_interface_binding(decl)
  if decl.type_params.any?
    type_param_names = decl.type_params.map(&:name)
    type_params_map = type_param_names.map { |n| [n, Types::TypeVar.new(n)] }.to_h
    methods = {}

    decl.methods.each do |method_decl|
      method = resolve_interface_method_binding(method_decl, type_params: type_params_map, type_param_constraints: {})
      raise_sema_error("duplicate method #{decl.name}.#{method.name}") if methods.key?(method.name)

      methods[method.name] = method
    end

    GenericInterfaceBinding.new(
      name: decl.name,
      type_params: type_param_names.freeze,
      type_param_constraints: {},
      methods: methods.freeze,
      ast: decl,
      module_name: @ctx.module_name,
    )
  else
    methods = {}

    decl.methods.each do |method_decl|
      method = resolve_interface_method_binding(method_decl)
      raise_sema_error("duplicate method #{decl.name}.#{method.name}") if methods.key?(method.name)

      methods[method.name] = method
    end

    InterfaceBinding.new(
      name: decl.name,
      methods: methods.freeze,
      ast: decl,
      module_name: @ctx.module_name,
    )
  end
end

#declare_named_types ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 218

def declare_named_types
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      case decl
      when AST::StructDecl
        validate_struct_layout!(decl)
        validate_explicit_aggregate_c_name!(decl)
        ensure_available_type_name!(decl.name)
        @ctx.types[decl.name] = if decl.type_params.empty?
          Types::Struct.new(
            decl.name,
            module_name: @ctx.module_name,
            external: raw_module?,
            packed: decl.packed,
            alignment: decl.alignment,
            linkage_name: decl.c_name,
            lifetime_params: decl.lifetime_params,
          )
        else
          Types::GenericStructDefinition.new(
            decl.name,
            decl.type_params.map(&:name),
            module_name: @ctx.module_name,
            external: raw_module?,
            packed: decl.packed,
            alignment: decl.alignment,
            linkage_name: decl.c_name,
            lifetime_params: decl.lifetime_params,
          )
        end
        register_nested_struct_types(decl)
      when AST::UnionDecl
        validate_explicit_aggregate_c_name!(decl)
        ensure_available_type_name!(decl.name)
        @ctx.types[decl.name] = Types::Union.new(decl.name, module_name: @ctx.module_name, external: raw_module?, linkage_name: decl.c_name)
      when AST::VariantDecl
        ensure_available_type_name!(decl.name)
        @ctx.types[decl.name] = if decl.type_params.empty?
          Types::Variant.new(decl.name, module_name: @ctx.module_name)
        else
          Types::GenericVariantDefinition.new(
            decl.name,
            decl.type_params.map(&:name),
            module_name: @ctx.module_name,
          )
        end
      when AST::EnumDecl
        ensure_available_type_name!(decl.name)
        @ctx.types[decl.name] = Types::Enum.new(decl.name, module_name: @ctx.module_name, external: raw_module?)
      when AST::FlagsDecl
        ensure_available_type_name!(decl.name)
        @ctx.types[decl.name] = Types::Flags.new(decl.name, module_name: @ctx.module_name, external: raw_module?)
      when AST::OpaqueDecl
        ensure_available_type_name!(decl.name)
        @ctx.types[decl.name] = Types::Opaque.new(
          decl.name,
          module_name: @ctx.module_name,
          external: raw_module?,
          linkage_name: decl.c_name,
        )
      when AST::InterfaceDecl
        ensure_available_type_name!(decl.name)
        @ctx.interfaces[decl.name] = declare_interface_binding(decl)
      end
    end
  rescue SemanticError => e
    collect_structural_error(e)
  end
end

#declare_top_level_values ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 735

def declare_top_level_values
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      case decl
      when AST::ConstDecl
        begin
          ensure_available_value_name!(decl.name, kind_label: "constant", line: decl.line, column: decl.column)
          type = resolve_type_ref(decl.type)
          validate_stored_ref_type!(type, "constant #{decl.name}")
          raise_sema_error("constant #{decl.name} cannot store proc values") if contains_proc_type?(type)
          @ctx.top_level_values[decl.name] = value_binding(
            name: decl.name,
            type: type,
            mutable: false,
            kind: :const,
          )
        rescue SemanticError => e
          collect_structural_error(e)
          @ctx.top_level_values[decl.name] = value_binding(
            name: decl.name,
            type: @error_type,
            mutable: false,
            kind: :const,
          ) unless @ctx.top_level_values.key?(decl.name)
        end
      when AST::VarDecl
        ensure_available_value_name!(decl.name, kind_label: "module variable", line: decl.line, column: decl.column)
        raise_sema_error("module variable #{decl.name} requires an explicit type") unless decl.type

        type = resolve_type_ref(decl.type)
        validate_stored_ref_type!(type, "module variable #{decl.name}")
        @ctx.top_level_values[decl.name] = value_binding(
          name: decl.name,
          type: type,
          mutable: true,
          kind: :var,
        )
      when AST::EventDecl
        ensure_available_value_name!(decl.name, kind_label: "event", line: decl.line, column: decl.column)
        @ctx.top_level_values[decl.name] = value_binding(
          name: decl.name,
          type: resolve_event_decl_type(decl),
          mutable: false,
          kind: :event,
        )
      end
    end
  rescue SemanticError => e
    collect_structural_error(e)
  end
end

#define_nested_type_bindings_recursive(parent_decl, parent_name: parent_decl.name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 792

def define_nested_type_bindings_recursive(parent_decl, parent_name: parent_decl.name)
  parent_decl.nested_types.each do |nested|
    qualified_name = "#{parent_name}.#{nested.name}"
    nested_type = @ctx.types[qualified_name]
    next unless nested_type.is_a?(Types::Struct)
    nested_scope = resolve_nested_type_bindings(nested, parent_name: qualified_name)
    nested_type.define_nested_types(nested_scope)
    define_nested_type_bindings_recursive(nested, parent_name: qualified_name)
  end
end

#describe_expression(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 348

def describe_expression(expression)
  case expression
  when AST::Identifier
    expression.name
  when AST::MemberAccess
    "#{describe_expression(expression.receiver)}.#{expression.member}"
  when AST::IndexAccess
    "#{describe_expression(expression.receiver)}[...]"
  when AST::Specialization
    "#{describe_expression(expression.callee)}[...]"
  when AST::FormatString
    'f"..."'
  else
    expression.class.name.split("::").last
  end
end

#direct_function_identity_expression?(expression, scopes) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 93

def direct_function_identity_expression?(expression, scopes)
  case expression
  when AST::Identifier
    return false if lookup_value(expression.name, scopes)
    return false unless @ctx.top_level_functions.key?(expression.name)

    binding = @ctx.top_level_functions.fetch(expression.name)
    !binding.type_params.any? && !foreign_function_binding?(binding)
  when AST::MemberAccess
    return false unless expression.receiver.is_a?(AST::Identifier) && @ctx.imports.key?(expression.receiver.name)

    imported_module = @ctx.imports.fetch(expression.receiver.name)
    return false unless imported_module.functions.key?(expression.member)

    binding = imported_module.functions.fetch(expression.member)
    !binding.type_params.any? && !foreign_function_binding?(binding)
  when AST::Specialization
    binding = resolve_specialized_function_binding(expression)
    binding && !foreign_function_binding?(binding)
  else
    false
  end
end

#direct_function_to_proc_argument_compatible?(actual_type, expected_type, expression, scopes) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 78

def direct_function_to_proc_argument_compatible?(actual_type, expected_type, expression, scopes)
  return false unless expression
  return false unless actual_type.is_a?(Types::Function) && proc_type?(expected_type)
  return false unless direct_function_identity_expression?(expression, scopes)

  function_type_matches_proc_type?(actual_type, expected_type)
end

#direct_task_to_proc_argument_compatible?(actual_type, expected_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 86

def direct_task_to_proc_argument_compatible?(actual_type, expected_type)
  return false unless actual_type.is_a?(Types::Task)
  return false unless task_root_proc_type?(expected_type)

  actual_type == expected_type.return_type
end

#each_enum_match_arm(statement, scrutinee_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 590

def each_enum_match_arm(statement, scrutinee_type, scopes:)
  covered_members = {}
  wildcard_seen = false
  statement.arms.each do |arm|
    if arm.pattern.is_a?(AST::ErrorExpr)
      yield arm, scopes
      next
    end

    if wildcard_pattern?(arm.pattern)
      raise_sema_error("duplicate wildcard arm in match") if wildcard_seen
      wildcard_seen = true
      yield arm, scopes
      next
    end
    validate_consuming_foreign_expression!(arm.pattern, scopes:, root_allowed: false)
    validate_hoistable_foreign_expression!(arm.pattern, scopes:, root_hoistable: false)
    pattern_type = infer_expression(arm.pattern, scopes:, expected_type: scrutinee_type)
    ensure_assignable!(pattern_type, scrutinee_type, "match arm expects #{scrutinee_type}, got #{pattern_type}")

    member_name = match_member_name(arm.pattern, scrutinee_type)
    raise_sema_error("match arm must be an enum member of #{scrutinee_type}") unless member_name
    raise_sema_error("duplicate match arm #{scrutinee_type}.#{member_name}") if covered_members.key?(member_name)

    covered_members[member_name] = true
    yield arm, scopes
  end

  return if wildcard_seen

  missing_members = scrutinee_type.members - covered_members.keys
  return if missing_members.empty?

  raise_sema_error("match on #{scrutinee_type} is missing cases: #{missing_members.join(', ')}")
end

#each_integer_match_arm(statement, scrutinee_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 626

def each_integer_match_arm(statement, scrutinee_type, scopes:)
  has_wildcard = statement.arms.any? { |arm| wildcard_pattern?(arm.pattern) }
  raise_sema_error("match on integer type #{scrutinee_type} requires a wildcard arm (_:)") unless has_wildcard

  covered_values = {}
  wildcard_seen = false
  statement.arms.each do |arm|
    if arm.pattern.is_a?(AST::ErrorExpr)
      yield arm
      next
    end

    if wildcard_pattern?(arm.pattern)
      raise_sema_error("duplicate wildcard arm in match") if wildcard_seen
      wildcard_seen = true
      yield arm
      next
    end

    if arm.pattern.is_a?(AST::RangeExpr)
      start_val = arm.pattern.start_expr
      end_val   = arm.pattern.end_expr
      unless (start_val.is_a?(AST::IntegerLiteral) || start_val.is_a?(AST::CharLiteral)) &&
             (end_val.is_a?(AST::IntegerLiteral) || end_val.is_a?(AST::CharLiteral))
        raise_sema_error("range match arm bounds must be integer or char literals, got #{start_val.class.name}..#{end_val.class.name}")
      end

      raise_sema_error("range match arm start #{start_val.value} must be <= end #{end_val.value}") if start_val.value > end_val.value

      range_key = [start_val.value, end_val.value]
      raise_sema_error("duplicate match arm range #{range_key[0]}..#{range_key[1]}") if covered_values.key?(range_key)

      covered_values[range_key] = true
      yield arm
      next
    end

    unless arm.pattern.is_a?(AST::IntegerLiteral) || arm.pattern.is_a?(AST::CharLiteral)
      raise_sema_error("match arm for integer scrutinee must be an integer literal, char literal, range, or _, got #{arm.pattern.class.name}")
    end

    value = arm.pattern.value
    raise_sema_error("duplicate match arm value #{value}") if covered_values.key?(value)

    covered_values[value] = true
    yield arm
  end
end

#each_string_match_arm(statement, scrutinee_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 675

def each_string_match_arm(statement, scrutinee_type, scopes:)
  has_wildcard = statement.arms.any? { |arm| wildcard_pattern?(arm.pattern) }
  raise_sema_error("match on str requires a wildcard arm (_:)") unless has_wildcard

  covered_values = {}
  wildcard_seen = false
  statement.arms.each do |arm|
    if arm.pattern.is_a?(AST::ErrorExpr)
      yield arm
      next
    end

    if wildcard_pattern?(arm.pattern)
      raise_sema_error("duplicate wildcard arm in match") if wildcard_seen
      wildcard_seen = true
      yield arm
      next
    end

    unless arm.pattern.is_a?(AST::StringLiteral)
      raise_sema_error("match arm for str scrutinee must be a string literal or _, got #{arm.pattern.class.name}")
    end

    value = arm.pattern.value
    raise_sema_error("duplicate match arm value \"#{value}\"") if covered_values.key?(value)

    covered_values[value] = true
    yield arm
  end
end

#each_tuple_match_arm(statement, scrutinee_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 706

def each_tuple_match_arm(statement, scrutinee_type, scopes:)
  has_wildcard = statement.arms.any? { |arm| wildcard_pattern?(arm.pattern) }
  raise_sema_error("match on tuple type #{scrutinee_type} requires a wildcard arm (_:)") unless has_wildcard

  arity = scrutinee_type.element_types.length
  covered_values = {}
  wildcard_seen = false

  statement.arms.each do |arm|
    if arm.pattern.is_a?(AST::ErrorExpr)
      yield arm
      next
    end

    if wildcard_pattern?(arm.pattern)
      raise_sema_error("duplicate wildcard arm in match") if wildcard_seen
      wildcard_seen = true
      yield arm
      next
    end

    unless arm.pattern.is_a?(AST::ExpressionList)
      raise_sema_error("match arm for tuple scrutinee must be a tuple literal or _, got #{arm.pattern.class.name}")
    end

    elements = arm.pattern.elements
    raise_sema_error("tuple match arm has #{elements.length} elements but scrutinee has #{arity}") unless elements.length == arity

    values = elements.map do |elem|
      if elem.is_a?(AST::Identifier) && elem.name == "_"
        :wildcard
      elsif elem.is_a?(AST::IntegerLiteral) || elem.is_a?(AST::CharLiteral) ||
            elem.is_a?(AST::StringLiteral) || elem.is_a?(AST::BooleanLiteral)
        elem.value
      else
        raise_sema_error("tuple match arm element must be a literal or _, got #{elem.class.name}")
      end
    end

    all_literal = values.all? { |v| v != :wildcard }
    if all_literal
      raise_sema_error("duplicate tuple match arm #{arm.pattern.elements.map { |e| e.respond_to?(:value) ? e.value.inspect : '_' }.join(', ')}") if covered_values.key?(values)
      covered_values[values] = true
    end

    yield arm
  end
end

#each_variant_match_arm(statement, scrutinee_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 825

def each_variant_match_arm(statement, scrutinee_type, scopes:)
  covered_arms = {}
  wildcard_seen = false
  equality_cover_table = {}
  statement.arms.each do |arm|
    if arm.pattern.is_a?(AST::ErrorExpr)
      yield arm, scopes
      next
    end

    if wildcard_pattern?(arm.pattern)
      raise_sema_error("duplicate wildcard arm in match") if wildcard_seen
      wildcard_seen = true
      yield arm, scopes
      next
    end
    validate_consuming_foreign_expression!(arm.pattern, scopes:, root_allowed: false)
    validate_hoistable_foreign_expression!(arm.pattern, scopes:, root_hoistable: false)

    arm_name = variant_match_arm_name(arm.pattern, scrutinee_type)
    raise_sema_error("match arm must be a variant arm of #{scrutinee_type}") unless arm_name

    arm_scopes = scopes.dup
    has_guards = false
    equality_cover = {}

    if arm.pattern.is_a?(AST::Call) && !arm.pattern.arguments.empty?
      has_guards, equality_cover = check_struct_match_pattern(arm.pattern.arguments, arm_name, scrutinee_type, arm_scopes, scopes:, arm:)
    end

    unless has_guards
      raise_sema_error("duplicate match arm #{scrutinee_type}.#{arm_name}") if covered_arms.key?(arm_name)
      covered_arms[arm_name] = true
    else
      equality_cover_table[arm_name] = merge_equality_cover(equality_cover_table[arm_name], equality_cover)
    end

    if arm.binding_name
      ensure_non_reserved_primitive_name!(arm.binding_name, kind_label: "match binding", line: arm.binding_line, column: arm.binding_column)
      fields = scrutinee_type.arm(arm_name)
      if fields.nil? || fields.empty?
        raise_sema_error("variant arm #{scrutinee_type}.#{arm_name} has no payload; 'as' binding is not allowed")
      end

      payload_type = Types::VariantArmPayload.new(scrutinee_type, arm_name, fields)
      binding = value_binding(
        name: arm.binding_name,
        type: payload_type,
        mutable: true,
        kind: :local,
        id: @preassigned_local_binding_ids[arm.object_id],
      )
      arm_scopes = arm_scopes + [{ arm.binding_name => binding }]
      record_declaration_binding(arm, binding)
    end
    yield arm, arm_scopes
  end

  equality_cover_table.each do |arm_name, field_covers|
    next if covered_arms.key?(arm_name)
    payload_fields = scrutinee_type.arm(arm_name)
    next unless payload_fields
    covered = field_covers.any? do |field_name, covered_members|
      field_type = payload_fields[field_name]
      next unless field_type.is_a?(Types::Enum)
      all_members = field_type.members
      all_members.any? && (all_members - covered_members).empty?
    end
    covered_arms[arm_name] = true if covered
  end

  return if wildcard_seen

  missing_arms = scrutinee_type.arm_names - covered_arms.keys
  return if missing_arms.empty?

  raise_sema_error("match on #{scrutinee_type} is missing cases: #{missing_arms.join(', ')}")
end

#empty_module_binding(module_path) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 180

def empty_module_binding(module_path)
  ModuleBinding.new(
    name: module_path,
    types: {}, type_declarations: {}, interfaces: {},
    attributes: {}, attribute_applications: {},
    values: {}, functions: {}, methods: {},
    implemented_interfaces: {}, imports: {},
    private_types: {}, private_interfaces: {}, private_attributes: {},
    private_values: {}, private_functions: {}, private_methods: {},
    private_implemented_interfaces: {},
  )
end

#ensure_argument_assignable!(actual_type, expected_type, external:, message:, expression: nil, scopes: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 483

def ensure_argument_assignable!(actual_type, expected_type, external:, message:, expression: nil, scopes: nil)
  line = source_line(expression)
  column = source_column(expression)
  unless argument_types_compatible?(actual_type, expected_type, external:, expression:, scopes:)
    suggestion = explicit_cast_suggestion(actual_type, expected_type)
    raise SemanticError.new(message, line:, column:, path: @path, suggestion:)
  end
end

#ensure_assignable!(actual_type, expected_type, message, expression: nil, scopes: nil, external_numeric: false, external_pointer_null: false, contextual_int_to_float: false, line: nil, column: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 449

def ensure_assignable!(actual_type, expected_type, message, expression: nil, scopes: nil, external_numeric: false, external_pointer_null: false, contextual_int_to_float: false, line: nil, column: nil)
  line ||= source_line(expression)
  column ||= source_column(expression)

  unless types_compatible?(actual_type, expected_type, expression:, scopes:, external_numeric:, external_pointer_null:, contextual_int_to_float:)
    suggestion = explicit_cast_suggestion(actual_type, expected_type)
    raise SemanticError.new(message, line:, column:, path: @path, suggestion:)
  end
end

#ensure_available_type_name!(name, line: nil, column: nil, length: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 705

def ensure_available_type_name!(name, line: nil, column: nil, length: nil)
  unless raw_module? || (PRELUDE_TYPE_DEFINING_MODULES[name] == @ctx.module_name)
    ensure_non_reserved_type_binding_name!(name, kind_label: "type", line:, column:, length:)
  end
  raise_sema_error("duplicate type #{name}") if @ctx.types.key?(name) || @ctx.interfaces.key?(name)
end

#ensure_available_value_name!(name, kind_label: "value", line: nil, column: nil, length: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 712

def ensure_available_value_name!(name, kind_label: "value", line: nil, column: nil, length: nil)
  ensure_non_reserved_value_type_name!(name, kind_label:, line:, column:, length:)
  raise_sema_error("duplicate value #{name}") if @ctx.top_level_values.key?(name) || @ctx.top_level_functions.key?(name)
end

#ensure_non_reserved_import_alias_name!(name, kind_label:, line: nil, column: nil, length: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 727

def ensure_non_reserved_import_alias_name!(name, kind_label:, line: nil, column: nil, length: nil)
  ensure_non_reserved_name!(name, Types::RESERVED_IMPORT_ALIAS_NAMES, kind_label:, line:, column:, length:)
end

#ensure_non_reserved_name!(name, reserved_names, kind_label:, line: nil, column: nil, length: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 717

def ensure_non_reserved_name!(name, reserved_names, kind_label:, line: nil, column: nil, length: nil)
  return unless reserved_names.include?(name)

  raise_sema_error("#{kind_label} #{name} uses reserved built-in type name #{name}", line:, column:, length:)
end

#ensure_non_reserved_primitive_name!(name, kind_label:, line: nil, column: nil, length: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 787

def ensure_non_reserved_primitive_name!(name, kind_label:, line: nil, column: nil, length: nil)
  ensure_non_reserved_value_type_name!(name, kind_label:, line:, column:, length:)
end

#ensure_non_reserved_type_binding_name!(name, kind_label:, line: nil, column: nil, length: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 731

def ensure_non_reserved_type_binding_name!(name, kind_label:, line: nil, column: nil, length: nil)
  ensure_non_reserved_name!(name, Types::RESERVED_TYPE_BINDING_NAMES, kind_label:, line:, column:, length:)
end

#ensure_non_reserved_value_type_name!(name, kind_label:, line: nil, column: nil, length: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 723

def ensure_non_reserved_value_type_name!(name, kind_label:, line: nil, column: nil, length: nil)
  ensure_non_reserved_name!(name, Types::RESERVED_VALUE_TYPE_NAMES, kind_label:, line:, column:, length:)
end

#ensure_parallel_for_static_lengths_match!(iterable_types) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1116

def ensure_parallel_for_static_lengths_match!(iterable_types)
  lengths = iterable_types.filter_map { |iterable_type| array_type?(iterable_type) ? array_length(iterable_type) : nil }
  return if lengths.empty? || lengths.all? { |length| length == lengths.first }

  raise_sema_error("parallel for iterables must have matching lengths")
end

#error_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1219

def error_type?(type)
  type.is_a?(Types::Error)
end

#evaluate_attribute_arg_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 525

def evaluate_attribute_arg_call(arguments, scopes:)
  attribute_handle = evaluate_compile_time_const_value(arguments.first.value, scopes:)
  return nil unless attribute_handle.is_a?(Types::AttributeHandle)

  param_name = reflection_identifier_name(arguments[1].value, context: "attribute_arg")
  return nil unless attribute_handle.argument_values

  attribute_handle.argument_values[param_name]
end

#evaluate_attribute_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 508

def evaluate_attribute_of_call(arguments, scopes:)
  target = evaluate_reflection_target_argument(arguments.first.value, scopes:)
  binding = resolve_attribute_name_argument(arguments[1].value)
  validate_attribute_target_compatibility!(target, binding)

  application = find_attribute_application(target, binding)
  return nil unless application

  Types::AttributeHandle.new(
    binding.name,
    binding.module_name,
    target,
    binding.params,
    application.argument_values,
  )
end

#evaluate_attributes_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 572

def evaluate_attributes_of_call(arguments, scopes:)
  raise_sema_error("attributes_of expects 1 or 2 arguments") unless (1..2).include?(arguments.length)

  target = evaluate_reflection_target_argument(arguments.first.value, scopes:)

  if arguments.length == 2
    attribute_binding = resolve_attribute_name_argument(arguments[1].value)
    application = find_attribute_application(target, attribute_binding)
    return [] unless application

    [Types::AttributeHandle.new(
      attribute_binding.name,
      attribute_binding.module_name,
      target,
      attribute_binding.params,
      application.argument_values,
    )]
  else
    resolved_attribute_applications_for_target(target).map do |application|
      Types::AttributeHandle.new(
        application.binding.name,
        application.binding.module_name,
        target,
        application.binding.params,
        application.argument_values,
      )
    end
  end
end

#evaluate_block_body_const(decl, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 231

def evaluate_block_body_const(decl, name)
  @evaluating_const_values << name
  value = evaluate_compile_time_block(decl.block_body)
  @evaluating_const_values.pop
  set_const_value(name, value)
  value
end

#evaluate_callable_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1548

def evaluate_callable_of_call(arguments, scopes:)
  raise_sema_error("callable_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("callable_of expects 1 argument, got #{arguments.length}") unless arguments.length == 1

  resolve_callable_handle_argument(arguments.first.value, scopes:)
end

#evaluate_compile_time_block(statements, scopes: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 253

def evaluate_compile_time_block(statements, scopes: nil)
  ctx = CompileTime::BlockContext.new(self)
  result = ctx.evaluate_block(statements, scopes:)
  result
rescue CompileTime::ReturnValue => e
  e.value
rescue CompileTime::Error => e
  raise_sema_error(e.message)
end

#evaluate_compile_time_call(expression, scopes: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 322

def evaluate_compile_time_call(expression, scopes: nil)
  case expression.callee
  when AST::Identifier
    if (struct_type = @ctx.types[expression.callee.name]) && struct_type.is_a?(Types::Struct)
      fields = {}
      expression.arguments.each do |argument|
        val = CompileTime.evaluate(argument.value, resolve_identifier: lambda { |id|
          if scopes
            binding = lookup_value(id.name, scopes)
            return binding.const_value unless binding&.const_value.nil?
          end
          resolve_current_module_const_value(id.name)
        }, resolve_member_access: lambda { |ma|
          if (receiver_type = resolve_type_expression(ma.receiver))
            next resolve_enum_member_const_value(receiver_type, ma.member)
          end
          nil
        }, resolve_call: lambda { |inner_call|
          evaluate_compile_time_call(inner_call, scopes:)
        })
        return nil unless val
        fields[argument.name] = val
      end
      return fields
    end

    case expression.callee.name
    when "field_of"
      evaluate_field_of_call(expression.arguments, scopes: scopes || [])
    when "fields_of"
      evaluate_fields_of_call(expression.arguments)
    when "callable_of"
      evaluate_callable_of_call(expression.arguments, scopes: scopes || [])
    when "has_attribute"
      evaluate_has_attribute_call(expression.arguments, scopes: scopes || [])
    when "attribute_of"
      evaluate_attribute_of_call(expression.arguments, scopes: scopes || [])
    when "members_of"
      evaluate_members_of_call(expression.arguments)
    when "attributes_of"
      evaluate_attributes_of_call(expression.arguments, scopes: scopes || [])
    else
      func = @ctx.top_level_functions[expression.callee.name]
      if func&.ast&.respond_to?(:const) && func.ast.const
        evaluate_const_function_body(func, expression.arguments, scopes:)
      else
        evaluate_type_returning_call(expression, scopes:)
      end
    end
  when AST::Specialization
    if expression.callee.callee.is_a?(AST::Identifier) && expression.callee.callee.name == "attribute_arg"
      evaluate_attribute_arg_call(expression.arguments, scopes: scopes || [])
    else
      callee_name = expression.callee.callee.is_a?(AST::Identifier) ? expression.callee.callee.name : nil
      if callee_name
        resolved_type = begin
          resolve_type_expression(expression.callee)
        rescue SemanticError
          nil
        end
        if resolved_type && resolved_type.is_a?(Types::Struct)
          fields = {}
          expression.arguments.each do |argument|
            val = CompileTime.evaluate(argument.value, resolve_identifier: lambda { |id|
              if scopes
                binding = lookup_value(id.name, scopes)
                return binding.const_value unless binding&.const_value.nil?
              end
              resolve_current_module_const_value(id.name)
            }, resolve_member_access: lambda { |ma|
              if (receiver_type = resolve_type_expression(ma.receiver))
                next resolve_enum_member_const_value(receiver_type, ma.member)
              end
              nil
            }, resolve_call: lambda { |inner_call|
              evaluate_compile_time_call(inner_call, scopes:)
            })
            return nil unless val
            fields[argument.name] = val
          end
          return fields
        end
        func = @ctx.top_level_functions[callee_name]
        if func&.ast&.respond_to?(:const) && func.ast.const
          evaluate_const_function_body(func, expression.arguments, scopes:)
        else
          evaluate_type_returning_call(expression, scopes:)
        end
      else
        evaluate_type_returning_call(expression, scopes:)
      end
    end
  else
    nil
  end
end

#evaluate_compile_time_const_value(expression, scopes: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 263

def evaluate_compile_time_const_value(expression, scopes: nil)
  CompileTime.evaluate(
    expression,
    resolve_identifier: lambda do |identifier_expression|
      if scopes
        binding = lookup_value(identifier_expression.name, scopes)
        return binding.const_value unless binding&.const_value.nil?
      end

      value = resolve_current_module_const_value(identifier_expression.name)
      return value if value

      # Resolve a bare type-parameter name (e.g. `T`) to its substituted
      # concrete type so `inline if T == int` can fold at compile time.
      current_type_params[identifier_expression.name] || @ctx.types[identifier_expression.name]
    end,
    resolve_member_access: lambda do |member_access_expression|
      if member_access_expression.receiver.is_a?(AST::Identifier) && scopes
        binding = lookup_value(member_access_expression.receiver.name, scopes)
        if binding && binding.const_value
          receiver_value = binding.const_value
          case receiver_value
          when Types::FieldHandle
            case member_access_expression.member
            when "name" then next receiver_value.field_name
            when "type" then next receiver_value.struct_handle.struct_type.field(receiver_value.field_name)
            end
          when Types::MemberHandle
            case member_access_expression.member
            when "name" then next receiver_value.name
            when "value" then next receiver_value.value
            end
          when Types::AttributeHandle
            case member_access_expression.member
            when "name" then next receiver_value.name
            end
          end
        end
      end

      if (receiver_type = resolve_type_expression(member_access_expression.receiver))
        next resolve_enum_member_const_value(receiver_type, member_access_expression.member)
      end

      next unless member_access_expression.receiver.is_a?(AST::Identifier)

      resolve_imported_module_const_value(member_access_expression.receiver.name, member_access_expression.member)
    end,
    resolve_type_ref: lambda do |type_ref|
      resolve_type_ref(type_ref)
    end,
    resolve_call: lambda do |call_expression|
      evaluate_compile_time_call(call_expression, scopes:)
    end,
  )
rescue CompileTime::Error => e
  raise_sema_error(e.message)
end

#evaluate_const_function_body(func, arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 471

def evaluate_const_function_body(func, arguments, scopes:)
  return nil unless func.ast.params.length == arguments.length

  initial_vars = {}
  func.ast.params.each_with_index do |param, idx|
    arg_expr = arguments[idx].value
    arg_value = if scopes
      evaluate_compile_time_const_value(arg_expr, scopes:)
    else
      CompileTime.evaluate(
        arg_expr,
        resolve_identifier: lambda { |id| resolve_current_module_const_value(id.name) },
        resolve_member_access: nil,
        resolve_type_ref: lambda { |tr| resolve_type_ref(tr) },
        resolve_call: nil,
      )
    end
    return nil unless arg_value

    initial_vars[param.name] = arg_value
  end

  ctx = CompileTime::BlockContext.new(self, initial_variables: initial_vars)
  ctx.evaluate_block(func.ast.body, scopes: nil)
rescue CompileTime::ReturnValue => e
  e.value
rescue CompileTime::Error => e
  raise_sema_error(e.message)
end

#evaluate_enum_member_const_value(expression, enum_type:, member_values:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 602

def evaluate_enum_member_const_value(expression, enum_type:, member_values:)
  CompileTime.evaluate(
    expression,
    resolve_identifier: lambda do |identifier_expression|
      resolve_current_module_const_value(identifier_expression.name)
    end,
    resolve_member_access: lambda do |member_access_expression|
      if (receiver_type = resolve_type_expression(member_access_expression.receiver))
        next resolve_enum_member_const_value(
          receiver_type,
          member_access_expression.member,
          local_enum_type: enum_type,
          local_member_values: member_values,
        )
      end

      next unless member_access_expression.receiver.is_a?(AST::Identifier)

      resolve_imported_module_const_value(member_access_expression.receiver.name, member_access_expression.member)
    end,
    resolve_type_ref: lambda do |type_ref|
      resolve_type_ref(type_ref)
    end,
  )
end

#evaluate_field_of_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1536

def evaluate_field_of_call(arguments, scopes:)
  raise_sema_error("field_of does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("field_of expects 2 arguments, got #{arguments.length}") unless arguments.length == 2

  struct_handle = resolve_struct_handle_argument(arguments.first.value, scopes:)
  field_name = reflection_identifier_name(arguments[1].value, context: "field_of")
  field_handle = CompileTime::Reflection.core_field_handle(struct_handle, field_name)
  raise_sema_error("unknown field #{struct_handle.struct_type}.#{field_name}") unless field_handle

  field_handle
end

#evaluate_fields_of_call(arguments) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 547

def evaluate_fields_of_call(arguments)
  raise_sema_error("fields_of expects 1 argument") unless arguments.length == 1

  type = resolve_type_expression(arguments.first.value)
  raise_sema_error("fields_of requires a type argument") unless type

  handle = struct_handle_for_type(type)
  raise_sema_error("fields_of requires a struct type, got #{type}") unless handle

  CompileTime::Reflection.core_field_handles(handle)
end

#evaluate_has_attribute_call(arguments, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 501

def evaluate_has_attribute_call(arguments, scopes:)
  target = evaluate_reflection_target_argument(arguments.first.value, scopes:)
  binding = resolve_attribute_name_argument(arguments[1].value)
  validate_attribute_target_compatibility!(target, binding)
  !find_attribute_application(target, binding).nil?
end

#evaluate_members_of_call(arguments) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 559

def evaluate_members_of_call(arguments)
  raise_sema_error("members_of expects 1 argument") unless arguments.length == 1

  type = resolve_type_expression(arguments.first.value)
  raise_sema_error("members_of requires a type argument") unless type

  unless type.is_a?(Types::Enum) || type.is_a?(Types::Flags)
    raise_sema_error("members_of requires an enum or flags type, got #{type}")
  end

  CompileTime::Reflection.core_member_handles(type)
end

#evaluate_reflection_target_argument(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 535

def evaluate_reflection_target_argument(expression, scopes:)
  if (type_expr = resolve_type_expression(expression))
    handle = struct_handle_for_type(type_expr)
    return handle if handle
  end

  value = evaluate_compile_time_const_value(expression, scopes:)
  return value if value.is_a?(Types::FieldHandle) || value.is_a?(Types::CallableHandle)

  nil
end

#evaluate_top_level_const_value(name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 191

def evaluate_top_level_const_value(name)
  return @ctx.top_level_values.fetch(name).const_value if @evaluated_const_values.key?(name)

  raise_sema_error("cyclic constant value dependency involving #{name}") if @evaluating_const_values.include?(name)

  decl = @ctx.const_declarations.fetch(name)
  if decl.block_body
    return evaluate_block_body_const(decl, name)
  end

  if decl.value.is_a?(AST::ErrorExpr)
    @evaluated_const_values[name] = true
    return nil
  end

  @evaluating_const_values << name
  value = evaluate_compile_time_const_value(decl.value)
  @evaluating_const_values.pop

  if value.is_a?(Integer)
    binding_ = @ctx.top_level_values.fetch(name)
    check_type = binding_.type
    check_type = check_type.backing_type if check_type.respond_to?(:backing_type)

    if check_type.is_a?(Types::Primitive) && check_type.integer? && (width = check_type.integer_width)
      max_value = if check_type.signed_integer?
                    (1 << (width - 1)) - 1
                  else
                    (1 << width) - 1
                  end
      if value > max_value
        raise_sema_error("constant #{name} value #{value} does not fit in type #{binding_.type}")
      end
    end
  end

  set_const_value(name, value)
  value
end

#evaluate_type_returning_call(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 419

def evaluate_type_returning_call(expression, scopes:)
  callee_name, type_args = extract_type_callee_info(expression)
  return nil unless callee_name

  CompileTime::Reflection.core_evaluate_type_returning(
    callee_name, type_args,
    evaluate_value: ->(v) { evaluate_compile_time_const_value(v, scopes:) },
    resolve_type_ref: ->(tr) { resolve_type_ref(tr) },
    pointer_to: ->(t) { pointer_to(t) },
    const_pointer_to: ->(t) { const_pointer_to(t) },
    top_level_functions: ->(name) { @ctx.top_level_functions[name] },
    evaluate_type_returning_function_body: ->(func, targs) { evaluate_type_returning_function_body(func, targs) },
  )
end

#evaluate_type_returning_function_body(func, type_args) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 446

def evaluate_type_returning_function_body(func, type_args)
  value_params = func.ast.type_params.select { |p| p.is_a?(AST::ValueTypeParam) }
  return nil if value_params.empty?

  initial_vars = {}
  value_params.zip(type_args).each do |param, arg|
    arg_value = arg.value
    case arg_value
    when AST::IntegerLiteral
      initial_vars[param.name] = arg_value.value
    when AST::TypeRef
      initial_vars[param.name] = resolve_type_ref(arg_value)
    else
      return nil
    end
  end

  ctx = CompileTime::BlockContext.new(self, initial_variables: initial_vars)
  ctx.evaluate_block(func.ast.body, scopes: nil)
rescue CompileTime::ReturnValue => e
  e.value
rescue CompileTime::Error => e
  raise_sema_error(e.message)
end

#evaluate_when_discriminant(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1268

def evaluate_when_discriminant(expression)
  value = evaluate_compile_time_const_value(expression, scopes: [])
  raise_sema_error("when discriminant must be a compile-time constant", expression) if value.nil?

  value
end

#event_carrier_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 767

def event_carrier_type?(type)
  case type
  when Types::StructInstance
    type.definition.respond_to?(:has_events?) && type.definition.has_events?
  when Types::Struct
    type.respond_to?(:has_events?) && type.has_events?
  else
    false
  end
end

#event_listener_type(event_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 624

def event_listener_type(event_type)
  params = []
  params << Types::Registry.parameter("value", event_type.payload_type) if event_type.payload_type

  Types::Registry.function(
    nil,
    params:,
    return_type: @ctx.types.fetch("void"),
    external: false,
  )
end

#event_member_type(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 742

def event_member_type(receiver_type, name)
  return unless receiver_type.respond_to?(:event)

  receiver_type.event(name)
end

#event_method_kind(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 648

def event_method_kind(receiver_type, name)
  return unless event_type?(receiver_type)

  EVENT_METHOD_KINDS[name]
end

#event_method_name(kind) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 700

def event_method_name(kind)
  EVENT_METHOD_NAMES.fetch(kind)
end

#event_receiver_mutable?(receiver_expression, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 708

def event_receiver_mutable?(receiver_expression, scopes:)
  return true if top_level_event_receiver?(receiver_expression, scopes:)
  return false unless receiver_expression.is_a?(AST::MemberAccess)

  receiver_type = infer_lvalue_receiver(
    receiver_expression.receiver,
    scopes:,
    allow_ref_identifier: true,
    allow_pointer_identifier: true,
    require_mutable_pointer: true,
    allow_span_param_identifier: true,
  )
  receiver_type = project_field_receiver_type(receiver_type, require_mutable_pointer: true)
  !event_member_type(receiver_type, receiver_expression.member).nil?
rescue SemanticError
  false
end

#event_stateful_listener_type(event_type, state_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 636

def event_stateful_listener_type(event_type, state_type)
  params = [Types::Registry.parameter("state", Types::Registry.generic_instance("ptr", [state_type]))]
  params << Types::Registry.parameter("value", event_type.payload_type) if event_type.payload_type

  Types::Registry.function(
    nil,
    params:,
    return_type: @ctx.types.fetch("void"),
    external: false,
  )
end

#event_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 751

def event_type?(type)
  type.is_a?(Types::Event)
end

#event_visible_from_current_module?(event_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 704

def event_visible_from_current_module?(event_type)
  event_type.module_name == @ctx.module_name || event_type.visibility == :public
end

#exact_compile_time_numeric_compatibility?(actual_type, expression, expected_type, scopes: nil) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 133

def exact_compile_time_numeric_compatibility?(actual_type, expression, expected_type, scopes: nil)
  return false unless expected_type.is_a?(Types::Primitive) && expected_type.numeric?
  return false if actual_type.is_a?(Types::EnumBase)

  value = evaluate_compile_time_const_value(expression, scopes:)
  return false unless value.is_a?(Numeric)

  numeric_constant_fits_type?(value, expected_type)
end

#expanded_declarations ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 202

def expanded_declarations
  Enumerator.new do |yielder|
    @ctx.ast.declarations.each do |decl|
      case decl
      when AST::WhenStmt
        body = when_chosen_body(decl)
        if body
          body.each { |nested| yielder << nested }
        end
      else
        yielder << decl
      end
    end
  end
end

#explicit_cast_suggestion(actual_type, expected_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 459

def explicit_cast_suggestion(actual_type, expected_type)
  if expected_type.is_a?(Types::Span) && array_type?(actual_type) &&
     array_element_type(actual_type) == expected_type.element_type
    return "a span is a mutable view; the array must be a mutable addressable value — bind it with `var` (a `let` array does not coerce)"
  end

  if castable_primitive?(actual_type) && castable_primitive?(expected_type)
    return nil if actual_type == expected_type
    "use an explicit cast: `#{expected_type}<-(value)`"
  end

  if actual_type.is_a?(Types::Nullable) && expected_type.is_a?(Types::Nullable)
    explicit_cast_suggestion(actual_type.base, expected_type.base)
  else
    nil
  end
end

#explicit_declaration_type_for(stmt) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 489

def explicit_declaration_type_for(stmt)
  annotation = stmt.respond_to?(:type) ? stmt.type : nil
  return nil unless annotation

  name = annotation.respond_to?(:name) ? annotation.name : annotation.to_s
  @ctx.types[name]
end

#expression_contains_await?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 245

def expression_contains_await?(expression)
  case expression
  when AST::AwaitExpr
    true
  when AST::Call, AST::Specialization
    expression_contains_await?(expression.callee) || expression.arguments.any? { |argument| expression_contains_await?(argument.value) }
  when AST::UnaryOp
    expression_contains_await?(expression.operand)
  when AST::BinaryOp
    expression_contains_await?(expression.left) || expression_contains_await?(expression.right)
  when AST::IfExpr
    expression_contains_await?(expression.condition) || expression_contains_await?(expression.then_expression) || expression_contains_await?(expression.else_expression)
  when AST::MatchExpr
    expression_contains_await?(expression.expression) || expression.arms.any? { |arm| expression_contains_await?(arm.pattern) || expression_contains_await?(arm.value) }
  when AST::UnsafeExpr
    expression_contains_await?(expression.expression)
  when AST::PrefixCast
    expression_contains_await?(expression.expression)
  when AST::MemberAccess
    expression_contains_await?(expression.receiver)
  when AST::IndexAccess
    expression_contains_await?(expression.receiver) || expression_contains_await?(expression.index)
  when AST::FormatString
    expression.parts.any? { |part| part.is_a?(AST::FormatExprPart) && expression_contains_await?(part.expression) }
  else
    false
  end
end

#expression_end_line(node) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 235

def expression_end_line(node)
  return nil unless node

  lines = [node.line]

  case node
  when AST::MemberAccess
    lines << expression_end_line(node.receiver)
  when AST::IndexAccess
    lines << expression_end_line(node.receiver)
    lines << expression_end_line(node.index)
  when AST::Specialization
    lines << expression_end_line(node.callee)
  when AST::Call
    lines << expression_end_line(node.callee)
    node.arguments.each { |argument| lines << expression_end_line(argument.value) }
  when AST::Argument
    lines << expression_end_line(node.value)
  when AST::UnaryOp
    lines << expression_end_line(node.operand)
  when AST::BinaryOp
    lines << expression_end_line(node.left)
    lines << expression_end_line(node.right)
  when AST::IfExpr
    lines << expression_end_line(node.condition)
    lines << expression_end_line(node.then_expression)
    lines << expression_end_line(node.else_expression)
  when AST::MatchExpr
    lines << expression_end_line(node.expression)
    node.arms.each do |arm|
      lines << expression_end_line(arm.pattern)
      lines << expression_end_line(arm.value)
    end
  when AST::AwaitExpr
    lines << expression_end_line(node.expression)
  when AST::FormatExprPart
    lines << expression_end_line(node.expression)
  when AST::PrefixCast
    lines << expression_end_line(node.expression)
  end

  lines.compact.max
end

#extern_enum_integer_argument_compatibility?(actual_type, expected_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 157

def extern_enum_integer_argument_compatibility?(actual_type, expected_type)
  return unless actual_type.is_a?(Types::EnumBase)
  return unless expected_type.is_a?(Types::Primitive) && expected_type.integer? && expected_type.fixed_width_integer?

  backing_type = actual_type.backing_type
  return unless backing_type.is_a?(Types::Primitive) && backing_type.integer? && backing_type.fixed_width_integer?

  backing_type.integer_width == expected_type.integer_width
end

#external_numeric_assignment_target?(expression, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 124

def external_numeric_assignment_target?(expression, scopes:)
  case expression
  when AST::MemberAccess
    receiver_type = infer_field_receiver_type(expression.receiver, scopes:, require_mutable_pointer: true)
    receiver_type.respond_to?(:external) && receiver_type.external
  else
    false
  end
end

#external_void_pointer_argument_compatibility?(actual_type, expected_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 117

def external_void_pointer_argument_compatibility?(actual_type, expected_type)
  if actual_type.is_a?(Types::Nullable) && expected_type.is_a?(Types::Nullable)
    return external_void_pointer_argument_compatibility?(actual_type.base, expected_type.base)
  end

  return external_void_pointer_argument_compatibility?(actual_type, expected_type.base) if expected_type.is_a?(Types::Nullable)
  return false if actual_type.is_a?(Types::Nullable)
  return false unless pointer_type?(actual_type) && pointer_type?(expected_type)
  return false if const_pointer_type?(actual_type) && mutable_pointer_type?(expected_type)

  actual_pointee = pointee_type(actual_type)
  expected_pointee = pointee_type(expected_type)

  actual_pointee == @ctx.types.fetch("void") || expected_pointee == @ctx.types.fetch("void")
end

#extract_type_callee_info(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 434

def extract_type_callee_info(expression)
  if expression.is_a?(AST::Call) && expression.callee.is_a?(AST::Identifier)
    [expression.callee.name, nil]
  elsif expression.is_a?(AST::Specialization)
    if expression.callee.is_a?(AST::Identifier)
      [expression.callee.name, expression.arguments]
    elsif expression.callee.is_a?(AST::Specialization) && expression.callee.callee.is_a?(AST::Identifier)
      [expression.callee.callee.name, expression.callee.arguments]
    end
  end
end

#fallback_completion_type ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 497

def fallback_completion_type
  @ctx.types["int"] || @ctx.types.values.first
end

#fill_parameter_defaults!(by_position, params, binding, context_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 1040

def fill_parameter_defaults!(by_position, params, binding, context_name)
  return unless binding

  ast_params = binding.ast.params
  return unless ast_params.any? { |p| p.respond_to?(:default_value) && p.default_value }

  params.each_with_index do |param, idx|
    next unless by_position[idx].nil?
    next unless idx < ast_params.length

    ast_param = ast_params[idx]
    next unless ast_param.respond_to?(:default_value) && ast_param.default_value

    by_position[idx] = AST::Argument.new(name: nil, value: ast_param.default_value)
  end
end

#fill_positional_defaults!(arguments, binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 1057

def fill_positional_defaults!(arguments, binding)
  return unless binding.ast.params.any? { |p| p.respond_to?(:default_value) && p.default_value }

  ast_params = binding.ast.params
  while arguments.length < ast_params.length
    ast_param = ast_params[arguments.length]
    if ast_param.respond_to?(:default_value) && ast_param.default_value
      arguments << AST::Argument.new(name: nil, value: ast_param.default_value)
    else
      break
    end
  end
end

#finalize_top_level_const_values ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 187

def finalize_top_level_const_values
  @ctx.const_declarations.each_key { |name| evaluate_top_level_const_value(name) }
end

#find_attribute_application(target, binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 25

def find_attribute_application(target, binding)
  resolved_attribute_applications_for_target(target).find do |application|
    same_attribute_binding?(application.binding, binding)
  end
end

#find_reachable_imported_module(module_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 98

def find_reachable_imported_module(module_name)
  visited = {}

  @ctx.imports.each_value do |module_binding|
    found = find_reachable_imported_module_from(module_binding, module_name, visited)
    return found if found
  end

  nil
end

#find_reachable_imported_module_from(module_binding, module_name, visited) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 109

def find_reachable_imported_module_from(module_binding, module_name, visited)
  return nil unless module_binding
  return module_binding if module_binding.name == module_name
  return nil if visited[module_binding.name]

  visited[module_binding.name] = true
  module_binding.imports.each_value do |imported_module|
    found = find_reachable_imported_module_from(imported_module, module_name, visited)
    return found if found
  end

  nil
end

#finish_local_completion_frame(binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 111

def finish_local_completion_frame(binding)
  return if @active_local_completion_stack.empty?

  frame = @active_local_completion_stack.pop
  snapshots = frame[:snapshots]
  if snapshots.empty?
    return
  end

  start_line = [binding.ast.line, snapshots.first.line].compact.min
  end_line = snapshots.last.line

  # Extend end_line to cover the actual function body so that completion
  # and hover lookups resolve correctly even when snapshots don't reach
  # the final body line (common for generic functions whose bodies are
  # only partially analysed, and functions whose last statement does not
  # record a snapshot).
  if binding.ast.respond_to?(:body) && binding.ast.body
    body_end = last_ast_line(binding.ast.body)
    end_line = body_end if body_end && body_end > end_line
  end

  @local_completion_frames << LocalCompletionFrame.new(
    start_line:,
    end_line:,
    function_name: frame[:function_name],
    receiver_type: frame[:receiver_type],
    snapshots: snapshots.freeze,
  )
end

#float_literal_expression?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 888

def float_literal_expression?(expression)
  expression.is_a?(AST::FloatLiteral) ||
    (expression.is_a?(AST::UnaryOp) && ["+", "-"].include?(expression.operator) && float_literal_expression?(expression.operand))
end

#flow_refinements(expression, truthy:, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 68

def flow_refinements(expression, truthy:, scopes:)
  case expression
  when AST::Call
    if truthy && has_attribute_refinement_call?(expression)
      key = attribute_presence_key_from_call(expression, scopes:)
      return key ? { key => true } : {}
    end
  when AST::UnaryOp
    return flow_refinements(expression.operand, truthy: !truthy, scopes:) if expression.operator == "not"
  when AST::BinaryOp
    case expression.operator
    when "and"
      if truthy
        left_truthy = flow_refinements(expression.left, truthy: true, scopes:)
        right_scopes = scopes_with_refinements(scopes, left_truthy)
        right_truthy = flow_refinements(expression.right, truthy: true, scopes: right_scopes)
        return merge_refinements(left_truthy, right_truthy)
      end
    when "or"
      unless truthy
        left_falsy = flow_refinements(expression.left, truthy: false, scopes:)
        right_scopes = scopes_with_refinements(scopes, left_falsy)
        right_falsy = flow_refinements(expression.right, truthy: false, scopes: right_scopes)
        return merge_refinements(left_falsy, right_falsy)
      end
    when "==", "!="
      return null_test_refinements(expression, truthy:, scopes:)
    end
  end

  {}
end

#foreign_argument_actual_type(parameter, argument, scopes:, function_name:, expected_type: parameter.type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 119

def foreign_argument_actual_type(parameter, argument, scopes:, function_name:, expected_type: parameter.type)
  case parameter.passing_mode
  when :plain
    infer_expression(argument.value, scopes:, expected_type:)
  when :consuming
    foreign_consuming_argument_binding(parameter, argument, scopes:, function_name:)
    parameter.type
  when :in, :out, :inout
    if (legacy_passing_mode = foreign_argument_legacy_passing_mode(argument))
      raise_sema_error("argument #{parameter.name} to #{function_name} must not use #{legacy_passing_mode}; directional passing is declared on #{function_name}")
    end

    if parameter.passing_mode == :in
      infer_expression(argument.value, scopes:, expected_type: expected_type)
    else
      infer_lvalue(argument.value, scopes:)
    end
  else
    raise_sema_error("unsupported foreign passing mode #{parameter.passing_mode}")
  end
end

#foreign_argument_expression(argument) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 105

def foreign_argument_expression(argument)
  if argument.value.is_a?(AST::UnaryOp) && ["out", "in", "inout"].include?(argument.value.operator)
    argument.value.operand
  else
    argument.value
  end
end

#foreign_argument_legacy_passing_mode(argument) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 113

def foreign_argument_legacy_passing_mode(argument)
  return nil unless argument.value.is_a?(AST::UnaryOp) && ["out", "in", "inout"].include?(argument.value.operator)

  argument.value.operator
end

#foreign_boundary_nullable_pointer_like_base?(base) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 12

def foreign_boundary_nullable_pointer_like_base?(base)
  return true if base.is_a?(Types::Function) || base.is_a?(Types::Proc)
  return true if opaque_type?(base)
  return true if base == @ctx.types.fetch("cstr")

  pointer_type?(base) || const_pointer_type?(base) || ref_type?(base)
end

#foreign_call_consumes_binding?(binding) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1171

def foreign_call_consumes_binding?(binding)
  binding.type.params.any? { |parameter| parameter.passing_mode == :consuming }
end

#foreign_consuming_argument_binding(parameter, argument, scopes:, function_name:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 141

def foreign_consuming_argument_binding(parameter, argument, scopes:, function_name:)
  unless argument.value.is_a?(AST::Identifier)
    raise_sema_error("consuming argument #{parameter.name} to #{function_name} must be a bare nullable local or parameter binding")
  end

  binding = lookup_value(argument.value.name, scopes)
  unless binding && %i[let var param].include?(binding.kind) && binding.storage_type.is_a?(Types::Nullable) && binding.storage_type.base == parameter.type
    raise_sema_error("consuming argument #{parameter.name} to #{function_name} must be a bare nullable local or parameter binding")
  end

  binding
end

#foreign_cstr_argument_compatible?(actual_type, parameter, expression:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 32

def foreign_cstr_argument_compatible?(actual_type, parameter, expression:)
  types_compatible?(actual_type, parameter.type, expression:) || actual_type == @ctx.types.fetch("cstr")
end

#foreign_cstr_boundary_parameter?(parameter) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 28

def foreign_cstr_boundary_parameter?(parameter)
  parameter.boundary_type == @ctx.types.fetch("cstr") && parameter.type == @ctx.types.fetch("str")
end

#foreign_function_binding?(binding) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 79

def foreign_function_binding?(binding)
  binding.ast.is_a?(AST::ForeignFunctionDecl)
end

#foreign_mapping_auto_call_shorthand?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 92

def foreign_mapping_auto_call_shorthand?(expression)
  case expression
  when AST::Identifier
    true
  when AST::MemberAccess
    foreign_mapping_auto_call_shorthand?(expression.receiver)
  when AST::Specialization
    foreign_mapping_auto_call_shorthand?(expression.callee)
  else
    false
  end
end

#foreign_mapping_context? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 94

def foreign_mapping_context?
  @foreign_mapping_depth.positive?
end

#foreign_mapping_expression(decl) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 83

def foreign_mapping_expression(decl)
  return decl.mapping unless foreign_mapping_auto_call_shorthand?(decl.mapping)

  AST::Call.new(
    callee: decl.mapping,
    arguments: decl.params.map { |param| AST::Argument.new(name: nil, value: AST::Identifier.new(name: param.name)) },
  )
end

#foreign_mapping_public_alias_name(name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 65

def foreign_mapping_public_alias_name(name)
  "#{name}_public"
end

#foreign_mapping_reference_counts(expression, counts = Hash.new(0)) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1175

def foreign_mapping_reference_counts(expression, counts = Hash.new(0))
  case expression
  when AST::Identifier
    counts[expression.name] += 1
  when AST::MemberAccess
    foreign_mapping_reference_counts(expression.receiver, counts)
  when AST::IndexAccess
    foreign_mapping_reference_counts(expression.receiver, counts)
    foreign_mapping_reference_counts(expression.index, counts)
  when AST::Specialization, AST::Call
    foreign_mapping_reference_counts(expression.callee, counts)
    expression.arguments.each { |argument| foreign_mapping_reference_counts(argument.value, counts) }
  when AST::UnaryOp
    foreign_mapping_reference_counts(expression.operand, counts)
  when AST::BinaryOp
    foreign_mapping_reference_counts(expression.left, counts)
    foreign_mapping_reference_counts(expression.right, counts)
  when AST::IfExpr
    foreign_mapping_reference_counts(expression.condition, counts)
    foreign_mapping_reference_counts(expression.then_expression, counts)
    foreign_mapping_reference_counts(expression.else_expression, counts)
  when AST::UnsafeExpr
    foreign_mapping_reference_counts(expression.expression, counts)
  when AST::PrefixCast
    foreign_mapping_reference_counts(expression.expression, counts)
  end

  counts
end

#foreign_parameter_boundary_type(param, public_type, type_params:, type_param_constraints: current_type_param_constraints) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 36

def foreign_parameter_boundary_type(param, public_type, type_params:, type_param_constraints: current_type_param_constraints)
  return resolve_type_ref(param.boundary_type, type_params:, type_param_constraints:) if param.boundary_type
  return const_pointer_to(public_type) if param.mode == :in
  return pointer_to(foreign_slot_boundary_value_type(public_type)) if [:out, :inout].include?(param.mode)

  nil
end

#foreign_slot_boundary_value_type(public_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 44

def foreign_slot_boundary_value_type(public_type)
  if public_type.is_a?(Types::Nullable) && pointer_type?(public_type.base)
    return public_type.base
  end

  public_type
end

#format_string_integer_base_spec_supported?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1519

def format_string_integer_base_spec_supported?(type)
  resolved = type.is_a?(Types::EnumBase) ? type.backing_type : type
  resolved.is_a?(Types::Primitive) && resolved.integer?
end

#format_string_interpolation_supported?(type, context:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1524

def format_string_interpolation_supported?(type, context:)
  return true if type == @ctx.types.fetch("str")
  return true if type == @ctx.types.fetch("cstr")
  return true if type == @ctx.types.fetch("bool")
  return true if type.is_a?(Types::Primitive) && type.integer?
  return true if type.is_a?(Types::Primitive) && type.float?
  return true if type.is_a?(Types::EnumBase) && type.backing_type.is_a?(Types::Primitive) && type.backing_type.integer?
  return true if resolve_explicit_format_binding(type, context:)

  false
end

#freeze_scope_bindings(scope) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1104

def freeze_scope_bindings(scope)
  frozen_scope = scope.is_a?(FlowScope) ? FlowScope.new : {}
  scope.each do |name, binding|
    frozen_scope[name] = ValueBinding.new(
      id: binding.id,
      name: binding.name,
      storage_type: binding.storage_type,
      flow_type: binding.flow_type,
      mutable: false,
      kind: binding.kind,
      const_value: binding.const_value,
    )
  end
  frozen_scope
end

#fresh_noncopyable_event_initializer?(expression, target_type, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 748

def fresh_noncopyable_event_initializer?(expression, target_type, scopes:)
  return true unless expression

  case expression
  when AST::Call
    callable_kind, callable, _receiver = resolve_callable(expression.callee, scopes:)
    callable_kind == :struct && callable == target_type
  when AST::Specialization
    return false unless expression.callee.is_a?(AST::Identifier)
    return false unless %w[zero default].include?(expression.callee.name)
    return false unless expression.arguments.length == 1

    type_arg = expression.arguments.first.value
    type_arg.is_a?(AST::TypeRef) && resolve_type_ref(type_arg) == target_type
  else
    false
  end
rescue SemanticError
  false
end

#function_pointer_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 333

def function_pointer_type?(type)
  type.is_a?(Types::Function)
end

#function_type_for_name(name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 109

def function_type_for_name(name)
  @ctx.top_level_functions.fetch(name).type
end

#generic_integer_type_argument?(argument) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 790

def generic_integer_type_argument?(argument)
  integer_type_argument?(argument) || argument.is_a?(Types::TypeVar)
end

#harmonize_binary_float_literal_types(left_expression, right_expression, left_type, right_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 876

def harmonize_binary_float_literal_types(left_expression, right_expression, left_type, right_type, scopes:)
  if float_literal_expression?(left_expression) && right_type.is_a?(Types::Primitive) && right_type.float?
    left_type = infer_expression(left_expression, scopes:, expected_type: right_type)
  end

  if float_literal_expression?(right_expression) && left_type.is_a?(Types::Primitive) && left_type.float?
    right_type = infer_expression(right_expression, scopes:, expected_type: left_type)
  end

  [left_type, right_type]
end

#harmonize_binary_integer_literal_types(left_expression, right_expression, left_type, right_type, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 893

def harmonize_binary_integer_literal_types(left_expression, right_expression, left_type, right_type, scopes:)
  if integer_literal_expression?(left_expression) && right_type.is_a?(Types::Primitive) && right_type.integer?
    if exact_compile_time_numeric_compatibility?(left_type, left_expression, right_type, scopes:)
      left_type = infer_expression(left_expression, scopes:, expected_type: right_type)
    end
  end

  if integer_literal_expression?(right_expression) && left_type.is_a?(Types::Primitive) && left_type.integer?
    if exact_compile_time_numeric_compatibility?(right_type, right_expression, left_type, scopes:)
      right_type = infer_expression(right_expression, scopes:, expected_type: left_type)
    end
  end

  [left_type, right_type]
end

#has_attribute_refinement_call?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 171

def has_attribute_refinement_call?(expression)
  expression.callee.is_a?(AST::Identifier) && expression.callee.name == "has_attribute" && expression.arguments.length == 2 && expression.arguments.none?(&:name)
end

#implicit_ref_argument_compatible?(actual_type, expected_type, expression, scopes) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 16

def implicit_ref_argument_compatible?(actual_type, expected_type, expression, scopes)
  return false unless expression && scopes
  return false unless ref_type?(expected_type)
  return false unless actual_type == referenced_type(expected_type)
  return false unless safe_reference_source_expression?(expression, scopes:)

  infer_lvalue(expression, scopes:)
  true
rescue SemanticError
  false
end

#import_suggestion_for_type(type_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1426

def import_suggestion_for_type(type_name)
  return nil if @ctx.global_import_index.nil? || @ctx.global_import_index.empty?

  type_str = type_name.to_s
  return nil if type_str.empty?

  if @ctx.global_import_index.key?(type_str)
    entry = @ctx.global_import_index[type_str]
    return nil if entry.nil?
    module_path = entry.is_a?(Array) ? entry.first : entry
    if module_path && !@ctx.imports.key?(module_path.to_s.split(".").first) && !@ctx.imports.key?(module_path.to_s)
      return "type '#{type_str}' is available via 'import #{module_path}'"
    end
  end

  nil
end

#imported_module_binding_for_name(module_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1629

def imported_module_binding_for_name(module_name)
  @ctx.imports.each_value.find { |binding| binding.name == module_name }
end

#imported_module_with_private_method(receiver_type, method_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1005

def imported_module_with_private_method(receiver_type, method_name)
  imported_module = imported_module_with_private_method_local(receiver_type, method_name)
  return imported_module if imported_module

  fallback_owner = specialization_lookup_owner
  return nil unless fallback_owner

  fallback_owner.imported_module_with_private_method_local(receiver_type, method_name)
end

#imported_module_with_private_method_local(receiver_type, method_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1015

def imported_module_with_private_method_local(receiver_type, method_name)
  @ctx.imports.each_value do |module_binding|
    return module_binding if module_binding.private_method?(receiver_type, method_name)
  end

  nil
end

#infer_addr_source_type(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1282

def infer_addr_source_type(expression, scopes:)
  raise_sema_error("ref_of requires a mutable safe lvalue source") unless safe_reference_source_expression?(expression, scopes:)

  source_type = infer_lvalue(expression, scopes:)
  if contains_ref_type?(source_type)
    unless (source_type.is_a?(Types::Struct) || source_type.is_a?(Types::StructInstance)) && source_type.lifetime_params&.any?
      raise_sema_error("ref_of cannot target ref values")
    end
  end

  source_type
end

#infer_await_expression(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 867

def infer_await_expression(expression, scopes:)
  raise_sema_error("await is only allowed inside async functions") unless inside_async_function?

  task_type = infer_expression(expression.expression, scopes:)
  raise_sema_error("await expects Task[T], got #{task_type}") unless task_type.is_a?(Types::Task)

  task_type.result_type
end

#infer_binary(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 558

def infer_binary(expression, scopes:, expected_type: nil)
  propagated_type = propagating_expected_type(expression.operator, expected_type)
  left_type = infer_expression(expression.left, scopes:, expected_type: propagated_type)

  right_scopes = case expression.operator
                 when "and"
                   scopes_with_refinements(scopes, flow_refinements(expression.left, truthy: true, scopes:))
                 when "or"
                   scopes_with_refinements(scopes, flow_refinements(expression.left, truthy: false, scopes:))
                 else
                   scopes
                 end

  right_expected_type = case expression.operator
                        when "<<", ">>"
                          propagated_type || left_type
                        when "+", "-", "*", "/", "%"
                          propagated_type || left_type
                        when "|", "&", "^"
                          left_type
                        else
                          left_type
                        end

  right_type = infer_expression(expression.right, scopes: right_scopes, expected_type: right_expected_type)
  left_type, right_type = harmonize_binary_float_literal_types(
    expression.left,
    expression.right,
    left_type,
    right_type,
    scopes: right_scopes,
  )

  left_type, right_type = harmonize_binary_integer_literal_types(
    expression.left,
    expression.right,
    left_type,
    right_type,
    scopes: right_scopes,
  )

  case expression.operator
  when "and", "or"
    ensure_assignable!(left_type, @ctx.types.fetch("bool"), "operator #{expression.operator} requires bool operands")
    ensure_assignable!(right_type, @ctx.types.fetch("bool"), "operator #{expression.operator} requires bool operands")
    @ctx.types.fetch("bool")
  when "|", "&", "^"
    simd_result = simd_bitwise_result(left_type, right_type)
    return simd_result if simd_result

    # For Flags/Enum types, the operands must match and be bitwise-capable.
    unless left_type == right_type && (bitwise_type?(left_type) || left_type.is_a?(Types::Flags))
      raise_sema_error("operator #{expression.operator} requires matching integer or flags types, got #{left_type} and #{right_type}")
    end

    left_type
  when "+", "-", "*", "/"
    if expression.operator == "+" && (string_like_type?(left_type) || string_like_type?(right_type))
      raise_sema_error("operator + does not support str/cstr concatenation; use continued string literals for static text or string.String/str_buffer for dynamic text")
    end

    pointer_result = pointer_arithmetic_result(expression.operator, left_type, right_type)
    return pointer_result if pointer_result

    vector_result = vector_arithmetic_result(expression.operator, left_type, right_type)
    return vector_result if vector_result

    result_type = common_numeric_type(left_type, right_type)
    unless result_type
      if left_type.respond_to?(:signed_integer?) && right_type.respond_to?(:signed_integer?) &&
         left_type.integer? && right_type.integer? &&
         left_type.signed_integer? != right_type.signed_integer?
        raise_sema_error("operator #{expression.operator} requires compatible numeric types, got #{left_type} and #{right_type} (use an explicit cast to resolve signed/unsigned mismatch)")
      else
        raise_sema_error("operator #{expression.operator} requires compatible numeric types, got #{left_type} and #{right_type}")
      end
    end

    result_type
  when "%"
    simd_result = simd_mod_result(left_type, right_type)
    return simd_result if simd_result

    result_type = common_integer_type(left_type, right_type)
    unless result_type
      raise_sema_error("operator % requires compatible integer types, got #{left_type} and #{right_type}")
    end

    result_type
  when "<<", ">>"
    simd_result = simd_shift_result(left_type, right_type)
    return simd_result if simd_result

    unless left_type.is_a?(Types::Primitive) && left_type.integer? && right_type.is_a?(Types::Primitive) && right_type.integer?
      raise_sema_error("operator #{expression.operator} requires integer operands, got #{left_type} and #{right_type}")
    end

    left_type
  when "<", "<=", ">", ">="
    unless common_numeric_type(left_type, right_type)
      raise_sema_error("operator #{expression.operator} requires compatible numeric types, got #{left_type} and #{right_type}")
    end

    @ctx.types.fetch("bool")
  when "==", "!="
    unless c_natively_equality_comparable_type?(left_type) && c_natively_equality_comparable_type?(right_type)
      bad_type = c_natively_equality_comparable_type?(right_type) ? left_type : right_type
      if struct_instance_type?(bad_type)
        raise_sema_error("operator #{expression.operator} is not supported for struct type #{bad_type}; use equal[#{bad_type}](...) instead")
      else
        raise_sema_error("operator #{expression.operator} is not supported for type #{bad_type}")
      end
    end
    unless common_numeric_type(left_type, right_type) || types_compatible?(left_type, right_type) || types_compatible?(right_type, left_type)
      raise_sema_error("operator #{expression.operator} requires comparable types, got #{left_type} and #{right_type}")
    end

    @ctx.types.fetch("bool")
  else
    raise_sema_error("unsupported binary operator #{expression.operator}")
  end
end

#infer_call(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 925

def infer_call(expression, scopes:, expected_type: nil)
  callable_kind, callable, receiver = resolve_callable(expression.callee, scopes:)
  @resolved_call_kinds[@ctx.ast.node_ids[expression.callee.object_id]] = callable_kind

  case callable_kind
  when :function
    callable = specialize_function_binding(
      callable,
      expression.arguments,
      scopes:,
      receiver_type: callable_receiver_type_for_specialization(expression.callee, scopes:),
    )

    check_function_call(callable, expression.arguments, scopes:)
    validate_specialized_function_body(callable) unless callable.type_arguments.empty?
    callable.type.return_type
  when :method
    callable = specialize_function_binding(
      callable,
      expression.arguments,
      scopes:,
      receiver_type: infer_method_receiver_type(receiver, scopes:, member_name: expression.callee.member),
    ) if callable.type_params.any?
    record_editable_receiver_expression(receiver) if callable.type.receiver_editable
    raise_sema_error("cannot call editable method #{callable.name} on an immutable receiver") if callable.type.receiver_editable && !assignable_receiver?(receiver, scopes)

    check_function_call(callable, expression.arguments, scopes:)
    validate_specialized_function_body(callable) unless callable.type_arguments.empty?
    callable.type.return_type
  when :callable_value
    check_callable_value_call(callable, expression.arguments, scopes:, callee_expression: expression.callee)
    callable.return_type
  when :str_buffer_clear, :str_buffer_assign, :str_buffer_append, :str_buffer_assign_format, :str_buffer_append_format,
    :str_buffer_len, :str_buffer_capacity, :str_buffer_as_str, :str_buffer_as_cstr
    check_str_buffer_method_call(callable_kind, receiver, expression.arguments, scopes:)
  when :array_as_span
    raise_sema_error("as_span does not support named arguments") if expression.arguments.any?(&:name)
    raise_sema_error("as_span expects 0 arguments, got #{expression.arguments.length}") unless expression.arguments.empty?
    Types::Registry.span(array_element_type(callable))
  when :event_subscribe, :event_subscribe_once, :event_unsubscribe, :event_emit, :event_wait
    check_event_method_call(callable_kind, receiver, expression.arguments, scopes:)
  when :atomic_load, :atomic_store, :atomic_add, :atomic_sub, :atomic_exchange, :atomic_compare_exchange
    check_atomic_method_call(callable_kind, callable, receiver, expression.arguments, scopes:)
  when :simd_lane_with
    check_simd_method_call(callable_kind, callable, receiver, expression.arguments, scopes:)
  when :struct
    check_aggregate_construction(callable, expression.arguments, scopes:)
  when :simd
    check_simd_construction(callable, expression.arguments, scopes:)
  when :struct_with
    check_struct_with_call(callable, receiver, expression.arguments, scopes:)
  when :variant_arm_ctor
    check_variant_arm_construction(callable, expression.arguments, scopes:)
  when :array
    check_array_construction(callable, expression.arguments, scopes:)
  when :reinterpret
    check_reinterpret_call(callable, expression.arguments, scopes:)
  when :hash
    check_hash_call(callable, expression.arguments, scopes:)
  when :equal
    check_equal_call(callable, expression.arguments, scopes:)
  when :order
    check_order_call(callable, expression.arguments, scopes:)
  when :fatal
    check_fatal_call(expression.arguments, scopes:)
  when :ref_of
    check_ref_of_call(expression.arguments, scopes:)
  when :const_ptr_of
    check_const_ptr_of_call(expression.arguments, scopes:)
  when :read
    check_read_call(expression.arguments, scopes:)
  when :ptr_of
    check_ptr_of_call(expression.arguments, scopes:)
  when :field_of
    check_field_of_call(expression.arguments, scopes:)
  when :callable_of
    check_callable_of_call(expression.arguments, scopes:)
  when :attribute_of
    check_attribute_of_call(expression.arguments, scopes:)
  when :has_attribute
    check_has_attribute_call(expression.arguments, scopes:)
  when :get
    check_get_call(expression.arguments, scopes:)
  when :attribute_arg
    check_attribute_arg_call(callable, expression.arguments, scopes:)
  when :dyn_method
    check_dyn_method_call(callable, receiver, expression.arguments, scopes:)
    callable.return_type
  when :adapt
    check_adapt_call(callable, expression.arguments, scopes:)
  else
    raise_sema_error("#{describe_expression(expression.callee)} is not callable")
  end
end

#infer_call_return_type(call, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 543

def infer_call_return_type(call, scopes)
  callee = call.callee
  callee = callee.callee while callee.is_a?(AST::Specialization)

  case callee
  when AST::Identifier
    func = @ctx.top_level_functions[callee.name]
    return func.type.return_type if func

    member = callee.name
    this_binding = lookup_value("this", scopes)
    if this_binding && (rt = receiver_type_for_fields(this_binding.type))
      method = @ctx.methods.dig(rt, member)
      return method.type.return_type if method
    end
  when AST::MemberAccess
    name = resolve_receiver_name_for_call_inference(callee, scopes)
    member = callee.member
    return nil unless name

    if (import = @ctx.imports[name])
      func = import.functions[member]
      return func.type.return_type if func
    end

    receiver_type = @ctx.types[name]
    if receiver_type && @ctx.methods.key?(receiver_type)
      method = @ctx.methods[receiver_type]["static:#{member}"] || @ctx.methods[receiver_type][member]
      return method.type.return_type if method
    end
  end
  nil
end

#infer_enum_match_expression(expression, scrutinee_type, scopes:, expected_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 775

def infer_enum_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  arm_entries = []
  each_enum_match_arm(expression, scrutinee_type, scopes:) do |arm, arm_scopes|
    arm_entries << [infer_match_expression_arm_value(arm, scopes: arm_scopes, expected_type:), arm.value]
  end
  match_expression_common_type(arm_entries, expected_type)
end

#infer_expression(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 134

def infer_expression(expression, scopes:, expected_type: nil)
  with_error_node(expression) do
    type = case expression
           when AST::ErrorExpr
      expected_type || @error_type
    when AST::IntegerLiteral
      infer_integer_literal(expression, expected_type)
    when AST::FloatLiteral
      infer_float_literal(expression, expected_type)
    when AST::CharLiteral
      @ctx.types.fetch("ubyte")
    when AST::SizeofExpr
      unless check_layout_type_via_ct(expression.type, context: "size_of", scopes:)
        infer_layout_query_type(expression.type, context: "size_of")
      end
      @ctx.types.fetch("ptr_uint")
    when AST::AlignofExpr
      unless check_layout_type_via_ct(expression.type, context: "align_of", scopes:)
        infer_layout_query_type(expression.type, context: "align_of")
      end
      @ctx.types.fetch("ptr_uint")
    when AST::OffsetofExpr
      infer_offsetof_type(expression.type, expression.field, scopes:)
      resolve_and_store_offset(expression, scopes:)
      @ctx.types.fetch("ptr_uint")
    when AST::StringLiteral
      @ctx.types.fetch(expression.cstring ? "cstr" : "str")
    when AST::FormatString
      check_format_string_literal(expression, scopes:)
      @ctx.types.fetch("str")
    when AST::BooleanLiteral
      @ctx.types.fetch("bool")
    when AST::NullLiteral
      infer_null_literal(expression)
    when AST::Identifier
      infer_identifier(expression, scopes:, expected_type:)
    when AST::MemberAccess
      infer_member_access(expression, scopes:, expected_type:)
    when AST::IndexAccess
      infer_index_access(expression, scopes:)
    when AST::UnaryOp
      infer_unary(expression, scopes:, expected_type:)
    when AST::BinaryOp
      infer_binary(expression, scopes:, expected_type:)
    when AST::IfExpr
      infer_if_expression(expression, scopes:, expected_type:)
    when AST::MatchExpr
      infer_match_expression(expression, scopes:, expected_type:)
    when AST::UnsafeExpr
      infer_unsafe_expression(expression, scopes:, expected_type:)
    when AST::ProcExpr
      infer_proc_expression(expression, scopes:, expected_type:)
    when AST::AwaitExpr
      infer_await_expression(expression, scopes:)
    when AST::DetachExpr
      @uses_parallel_for = true
      validate_detach_expression!(expression.body.first&.expression || expression.body, scopes:)
      check_block(expression.body, scopes:, return_type: @ctx.types.fetch("void"), allow_return: false)
      Types::Handle.new
    when AST::Call
      infer_call(expression, scopes:, expected_type:)
    when AST::PrefixCast
      target_type = resolve_type_ref(expression.target_type)
      check_cast_call(target_type, [AST::Argument.new(name: nil, value: expression.expression)], scopes:)
      target_type
    when AST::Specialization
      if expression.callee.is_a?(AST::Identifier)
        if expression.callee.name == "zero"
          callable_kind, callable, = resolve_callable(expression, scopes:)
          return check_zero_call(callable, [], expected_type:) if callable_kind == :zero
        end

        if expression.callee.name == "default"
          resolution = resolve_default_specialization(expression)
          return resolution.target_type
        end
      end

      if (callable_resolution = resolve_specialized_callable_binding(expression, scopes:))
        callable_kind, function_binding, = callable_resolution
        raise_sema_error("specialized method #{describe_expression(expression)} must be called") if callable_kind == :method

        return function_binding.type
      end

      raise_sema_error("specialized name #{describe_expression(expression)} must be called")
    when AST::RangeExpr
      raise_sema_error("range expression can only be used as a for-loop iterable or range index target")
    when AST::ExpressionList
      if expected_type && expected_type.is_a?(Types::GenericInstance) && expected_type.name == "array"
        element_type = expected_type.arguments.first
        expression.elements.each do |element|
          value = element.is_a?(AST::Argument) ? element.value : element
          actual = infer_expression(value, scopes:, expected_type: element_type)
          ensure_assignable!(actual, element_type, "array element type mismatch: expected #{element_type}, got #{actual}", expression: value)
        end
        expected_type
      else
        names = []
        element_types = []
        expression.elements.each do |element|
          if element.is_a?(AST::Argument)
            names << element.name
            element_types << infer_expression(element.value, scopes:)
          else
            names << nil
            element_types << infer_expression(element, scopes:)
          end
        end
        has_named = names.any?
        Types::Registry.tuple(element_types, field_names: has_named ? names : nil)
      end
    else
      raise_sema_error("unsupported expression #{expression.class.name}")
    end

    @resolved_expr_types[@ctx.ast.node_ids[expression.object_id]] = type
    type
  end
end

#infer_field_handle_member(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1648

def infer_field_handle_member(expression, scopes:)
  case expression.member
  when "name"
    @ctx.types.fetch("str")
  when "type"
    handle = evaluate_compile_time_const_value(expression.receiver, scopes:)
    return @error_type unless handle.is_a?(Types::FieldHandle)

    resolve_type_ref(handle.field_declaration.type)
  else
    raise_sema_error("unknown member #{expression.member} of field_handle")
  end
end

#infer_field_receiver_type(receiver_expression, scopes:, require_mutable_pointer: false) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1319

def infer_field_receiver_type(receiver_expression, scopes:, require_mutable_pointer: false)
  receiver_type = infer_expression(receiver_expression, scopes:)
  project_field_receiver_type(receiver_type, require_mutable_pointer:)
end

#infer_float_literal(expression, expected_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 296

def infer_float_literal(expression, expected_type)
  if expression.lexeme.end_with?("f")
    @ctx.types.fetch("float")
  elsif expression.lexeme.end_with?("d")
    @ctx.types.fetch("double")
  elsif expected_type.is_a?(Types::Primitive) && expected_type.float?
    expected_type
  else
    @ctx.types.fetch("float")
  end
end

#infer_function_type_arguments(binding, arguments, scopes:, receiver_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 255

def infer_function_type_arguments(binding, arguments, scopes:, receiver_type: nil)
  expected_params = binding.type.params
  unless call_arity_matches?(binding.type, arguments.length)
    raise_sema_error(arity_error_message(binding.type, binding.name, arguments.length))
  end

  substitutions = infer_receiver_type_substitutions(binding, receiver_type)
  expected_params.each_with_index do |parameter, index|
    argument = arguments.fetch(index)
    candidate_type = substitute_type(parameter.type, substitutions)
    expected_argument_type = if callable_type?(candidate_type)
      candidate_type
    elsif contains_type_var?(candidate_type)
      nil
    else
      candidate_type
    end
    actual_type = foreign_argument_actual_type(parameter, argument, scopes:, function_name: binding.name, expected_type: expected_argument_type)
    collect_type_substitutions(parameter.type, actual_type, substitutions, binding.name)
  end

  binding.type_params.map do |name|
    inferred = substitutions[name]
    raise_sema_error("cannot infer type argument #{name} for function #{binding.name}") unless inferred

    raise_sema_error("generic function #{binding.name} cannot be instantiated with ref types") if contains_ref_type?(inferred)

    inferred
  end
end

#infer_identifier(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 308

def infer_identifier(expression, scopes:, expected_type: nil)
  binding = lookup_value(expression.name, scopes)
  if binding
    record_identifier_binding(expression, binding)
    return binding.type
  end

  if @ctx.top_level_functions.key?(expression.name)
    raise_sema_error("generic function #{expression.name} must be called") if @ctx.top_level_functions.fetch(expression.name).type_params.any?

    function_type = function_type_for_name(expression.name)
    if expected_type
      record_callable_value_identifier_site(expression)
      return function_type
    end

    raise_sema_error("function #{expression.name} must be called")
  end

  raise_sema_error("module #{expression.name} cannot be used as a value") if @ctx.imports.key?(expression.name)
  if @ctx.types.key?(expression.name)
    return Types::BUILTIN_TYPE_META_TYPE if expected_type.is_a?(Types::TypeType)
    return @ctx.types.fetch(expression.name)
  end

  if @ctx.top_level_functions && @ctx.types && scopes
    func_names = @ctx.top_level_functions.keys.map(&:to_s)
    type_names = @ctx.types.keys.map(&:to_s)
    scoped_names = scopes.flat_map { |s| s.is_a?(Hash) ? s.keys : [] }.map(&:to_s)
    suggestion = suggest_name(expression.name, func_names + type_names + scoped_names)
  end
  raise_sema_error("unknown name #{expression.name}", expression, suggestion: suggestion ? "did you mean '#{suggestion}'?" : nil)
end

#infer_if_expression(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 681

def infer_if_expression(expression, scopes:, expected_type: nil)
  condition_type = infer_expression(expression.condition, scopes:, expected_type: @ctx.types.fetch("bool"))
  ensure_assignable!(condition_type, @ctx.types.fetch("bool"), "if expression condition must be bool, got #{condition_type}")

  then_scopes = scopes_with_refinements(scopes, flow_refinements(expression.condition, truthy: true, scopes:))
  else_scopes = scopes_with_refinements(scopes, flow_refinements(expression.condition, truthy: false, scopes:))
  then_type = infer_expression(expression.then_expression, scopes: then_scopes, expected_type:)
  else_type = infer_expression(expression.else_expression, scopes: else_scopes, expected_type:)

  return expected_type if expected_type &&
    types_compatible?(then_type, expected_type, expression: expression.then_expression) &&
    types_compatible?(else_type, expected_type, expression: expression.else_expression)

  common_type = conditional_common_type(
    then_type,
    else_type,
    then_expression: expression.then_expression,
    else_expression: expression.else_expression,
  )
  return common_type if common_type

  raise_sema_error("if expression branches require compatible types, got #{then_type} and #{else_type}")
end

#infer_index_access(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 439

def infer_index_access(expression, scopes:)
  receiver_type = infer_expression(expression.receiver, scopes:)
  index_type = infer_expression(expression.index, scopes:)

  if soa_type?(receiver_type)
    return receiver_type.element_type
  end

  if simd_type?(receiver_type)
    return receiver_type.element_type
  end

  if array_type?(receiver_type) && !unsafe_context? && !addressable_storage_expression?(expression.receiver, scopes:)
    raise_sema_error("safe array indexing requires an addressable array value; bind it to a local first")
  end

  if array_type?(receiver_type) && expression.index.is_a?(AST::IntegerLiteral)
    length = array_length(receiver_type)
    index_val = expression.index.value
    if index_val >= length || index_val < 0
      raise_sema_error("array index #{index_val} is out of bounds for array[T, #{length}]", expression)
    end
  end

  if array_type?(receiver_type) && expression.index.is_a?(AST::UnaryOp) && expression.index.operator == "-" &&
     expression.index.operand.is_a?(AST::IntegerLiteral)
    length = array_length(receiver_type)
    index_val = -expression.index.operand.value
    raise_sema_error("array index #{index_val} is out of bounds for array[T, #{length}]", expression)
  end

  infer_index_result_type(receiver_type, index_type)
end

#infer_index_result_type(receiver_type, index_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 922

def infer_index_result_type(receiver_type, index_type)
  raise_sema_error("index must be an integer type, got #{index_type}") unless integer_type?(index_type)

  if array_type?(receiver_type)
    return array_element_type(receiver_type)
  end

  if span_type?(receiver_type)
    return receiver_type.element_type
  end

  if soa_type?(receiver_type)
    return receiver_type.element_type
  end

  if simd_type?(receiver_type)
    return receiver_type.element_type
  end

  if pointer_type?(receiver_type)
    require_unsafe!("pointer indexing requires unsafe") unless own_type?(receiver_type)

    return pointee_type(receiver_type)
  end

  raise_sema_error("cannot index #{receiver_type}")
end

#infer_integer_literal(expression, expected_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 266

def infer_integer_literal(expression, expected_type)
  # Integer type suffixes: 42u8, 0xFFub, 100uz, etc.
  suffix_type = integer_suffix_type(expression.lexeme)
  return @ctx.types.fetch(suffix_type) if suffix_type

  if expected_type.is_a?(Types::Primitive) && expected_type.integer? &&
     value_fits_integer_type?(expression.value, expected_type)
    expected_type
  else
    @ctx.types.fetch("int")
  end
end

#infer_integer_match_expression(expression, scrutinee_type, scopes:, expected_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 783

def infer_integer_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  arm_entries = []
  each_integer_match_arm(expression, scrutinee_type, scopes:) do |arm|
    arm_entries << [infer_match_expression_arm_value(arm, scopes:, expected_type:), arm.value]
  end
  match_expression_common_type(arm_entries, expected_type)
end

#infer_layout_query_type(type_ref, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 584

def infer_layout_query_type(type_ref, context:)
  type = resolve_type_ref(type_ref)
  return type if sized_layout_type?(type)

  raise_sema_error("#{context} requires a concrete sized type, got #{type_ref}")
end

#infer_local_initializer_type(stmt, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 483

def infer_local_initializer_type(stmt, scopes)
  return nil unless stmt.value

  infer_simple_local_type(stmt.value, scopes)
end

#infer_lvalue(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 6

def infer_lvalue(expression, scopes:)
  case expression
  when AST::Identifier
    binding = lookup_value(expression.name, scopes)
    unless binding
      scoped_names = scopes.flat_map { |s| s.is_a?(Hash) ? s.keys : [] }.map(&:to_s)
      suggestion = suggest_name(expression.name, scoped_names)
      raise_sema_error("unknown name #{expression.name}", expression, suggestion: suggestion ? "did you mean '#{suggestion}'?" : nil)
    end
    record_identifier_binding(expression, binding)
    raise_sema_error("cannot assign to immutable #{expression.name}") unless binding.mutable

    binding.storage_type
  when AST::MemberAccess
    receiver_type = infer_lvalue_receiver(expression.receiver, scopes:, allow_ref_identifier: true, allow_pointer_identifier: true, allow_span_param_identifier: true)
    receiver_type = project_field_receiver_type(receiver_type, require_mutable_pointer: true)
    unless aggregate_type?(receiver_type)
      raise_sema_error("cannot assign to member #{expression.member} of #{receiver_type}")
    end

    field_type = receiver_type.field(expression.member)
    raise_sema_error("unknown field #{receiver_type}.#{expression.member}") unless field_type

    field_type
  when AST::IndexAccess
    receiver_type = infer_lvalue_receiver(
      expression.receiver,
      scopes:,
      allow_pointer_identifier: true,
      require_mutable_pointer: true,
      allow_span_param_identifier: true,
    )

    index_type = infer_expression(expression.index, scopes:)
    infer_index_result_type(receiver_type, index_type)
  when AST::Call
    if read_call?(expression)
      validate_read_call_arguments!(expression.arguments)
      return infer_reference_value_type(expression.arguments.first.value, scopes:)
    end

    raise_sema_error("invalid assignment target")
  when AST::BinaryOp
    raise_sema_error("invalid assignment target")
  else
    raise_sema_error("invalid assignment target")
  end
end

#infer_lvalue_receiver(expression, scopes:, allow_ref_identifier: false, allow_pointer_identifier: false, require_mutable_pointer: false, allow_span_param_identifier: false) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 55

def infer_lvalue_receiver(expression, scopes:, allow_ref_identifier: false, allow_pointer_identifier: false, require_mutable_pointer: false, allow_span_param_identifier: false)
  case expression
  when AST::Identifier
    binding = lookup_value(expression.name, scopes)
    raise_sema_error("unknown name #{expression.name}") unless binding
    record_identifier_binding(expression, binding)

    return referenced_type(binding.type) if allow_ref_identifier && ref_type?(binding.type)
    if allow_pointer_identifier && pointer_type?(binding.type)
      require_unsafe!("raw pointer dereference requires unsafe") unless own_type?(binding.type)
      raise_sema_error("cannot assign through read-only raw pointer #{binding.type}") if require_mutable_pointer && const_pointer_type?(binding.type)

      return binding.type
    end
    if allow_span_param_identifier && binding.kind == :param && span_type?(binding.type)
      return binding.type
    end

    raise_sema_error("cannot assign through immutable #{expression.name}") unless binding.mutable

    binding.type
  when AST::MemberAccess
    receiver_type = infer_lvalue_receiver(
      expression.receiver,
      scopes:,
      allow_ref_identifier:,
      allow_pointer_identifier:,
      require_mutable_pointer:,
      allow_span_param_identifier:,
    )
    receiver_type = project_field_receiver_type(receiver_type, require_mutable_pointer:)
    unless aggregate_type?(receiver_type)
      raise_sema_error("cannot access member #{expression.member} of #{receiver_type}")
    end

    field_type = receiver_type.field(expression.member)
    raise_sema_error("unknown field #{receiver_type}.#{expression.member}") unless field_type

    field_type
  when AST::IndexAccess
    receiver_type = infer_lvalue_receiver(
      expression.receiver,
      scopes:,
      allow_ref_identifier:,
      allow_pointer_identifier:,
      require_mutable_pointer:,
      allow_span_param_identifier:,
    )
    index_type = infer_expression(expression.index, scopes:)
    infer_index_result_type(receiver_type, index_type)
  when AST::Call
    if read_call?(expression)
      validate_read_call_arguments!(expression.arguments)
      return infer_reference_value_type(expression.arguments.first.value, scopes:)
    end

    raise_sema_error("invalid assignment target")
  when AST::BinaryOp
    require_unsafe!("raw pointer arithmetic as lvalue receiver requires unsafe")
    type = infer_expression(expression, scopes:)
    raise_sema_error("binary op lvalue receiver must be a pointer") unless pointer_type?(type)
    raise_sema_error("cannot assign through read-only raw pointer #{type}") if require_mutable_pointer && const_pointer_type?(type)

    type
  else
    raise_sema_error("invalid assignment target")
  end
end

#infer_match_expression(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 732

def infer_match_expression(expression, scopes:, expected_type: nil)
  validate_consuming_foreign_expression!(expression.expression, scopes:, root_allowed: false)
  validate_hoistable_foreign_expression!(expression.expression, scopes:, root_hoistable: false)
  scrutinee_type = infer_expression(expression.expression, scopes:)

  if error_type?(scrutinee_type)
    infer_recovered_match_expression(expression, scopes:, expected_type:)
  elsif scrutinee_type.is_a?(Types::Enum)
    infer_enum_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  elsif scrutinee_type.is_a?(Types::Variant)
    infer_variant_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  elsif integer_type?(scrutinee_type)
    infer_integer_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  elsif scrutinee_type.is_a?(Types::StringView)
    infer_string_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  elsif scrutinee_type.is_a?(Types::Tuple)
    infer_tuple_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  else
    raise_sema_error("match requires an enum, variant, or integer scrutinee, got #{scrutinee_type}")
  end
end

#infer_match_expression_arm_value(arm, scopes:, expected_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 815

def infer_match_expression_arm_value(arm, scopes:, expected_type:)
  validate_consuming_foreign_expression!(arm.value, scopes:, root_allowed: false)
  validate_hoistable_foreign_expression!(arm.value, scopes:, root_hoistable: false)
  infer_expression(arm.value, scopes:, expected_type:)
end

#infer_member_access(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 342

def infer_member_access(expression, scopes:, expected_type: nil)
  type = resolve_type_expression(expression.receiver)
  if type
    return @error_type if error_type?(type)

    member_type = resolve_type_member(type, expression.member)
    return member_type if member_type

    if type.is_a?(Types::Variant) && type.arm_names.include?(expression.member)
      raise_sema_error("variant arm #{type}.#{expression.member} has payload; construct it with #{type}.#{expression.member}(field: value, ...)")
    end

    if (method = lookup_method(type, expression.member))
      raise_sema_error("associated function #{type}.#{expression.member} must be called") unless method.type.receiver_type.nil?
      raise_sema_error("method #{type}.#{expression.member} must be called")
    end

    raise_sema_error("unknown member #{type}.#{expression.member}")
  end

  if expression.receiver.is_a?(AST::Identifier) && @ctx.imports.key?(expression.receiver.name)
    imported_module = @ctx.imports.fetch(expression.receiver.name)
    value = imported_module.values[expression.member]
    return value.type if value

    if imported_module.functions.key?(expression.member)
      function = imported_module.functions.fetch(expression.member)
      raise_sema_error("generic function #{expression.receiver.name}.#{expression.member} must be called") if function.type_params.any?
      if expected_type
        record_callable_value_member_access_site(expression)
        return function.type
      end

      raise_sema_error("function #{expression.receiver.name}.#{expression.member} must be called")
    end

    if imported_module.types.key?(expression.member)
      raise_sema_error("type #{expression.receiver.name}.#{expression.member} cannot be used as a value")
    end

    if imported_module.private_value?(expression.member) || imported_module.private_function?(expression.member) || imported_module.private_type?(expression.member)
      raise_sema_error("#{expression.receiver.name}.#{expression.member} is private to module #{imported_module.name}")
    end

    raise_sema_error("unknown member #{expression.receiver.name}.#{expression.member}")
  end

  field_receiver_type = infer_field_receiver_type(expression.receiver, scopes:)
  method_receiver_type = infer_method_receiver_type(expression.receiver, scopes:, member_name: expression.member)
  return @error_type if error_type?(field_receiver_type) || error_type?(method_receiver_type)

  if array_type?(field_receiver_type) && expression.member == "as_span"
    element_type = array_element_type(field_receiver_type)
    return Types::Registry.span(element_type)
  end
  if char_array_removed_text_method?(method_receiver_type, expression.member)
    raise_sema_error("#{method_receiver_type}.#{expression.member} is not available; array[char, N] is raw storage, use str_buffer[N] or an explicit helper")
  end
  if str_buffer_type?(method_receiver_type) && str_buffer_method_kind(method_receiver_type, expression.member)
    raise_sema_error("method #{method_receiver_type}.#{expression.member} must be called")
  end
  if event_type?(method_receiver_type) && event_method_kind(method_receiver_type, expression.member)
    raise_sema_error("method #{method_receiver_type}.#{expression.member} must be called")
  end

  unless aggregate_type?(field_receiver_type)
    if field_receiver_type == builtin_field_handle_type
      return infer_field_handle_member(expression, scopes:)
    end
    if field_receiver_type == builtin_member_handle_type
      return infer_member_handle_member(expression)
    end
    raise_sema_error("cannot access member #{expression.member} of #{field_receiver_type}")
  end

  field_type = field_receiver_type.field(expression.member)
  return field_type if field_type

  if (event_type = event_member_type(field_receiver_type, expression.member))
    unless event_visible_from_current_module?(event_type)
      raise_sema_error("event #{field_receiver_type}.#{expression.member} is private to module #{event_type.module_name}")
    end

    return event_type
  end

  if lookup_method(method_receiver_type, expression.member)
    raise_sema_error("method #{method_receiver_type.name}.#{expression.member} must be called")
  end

  if (imported_module = imported_module_with_private_method(method_receiver_type, expression.member))
    raise_sema_error("#{method_receiver_type}.#{expression.member} is private to module #{imported_module.name}")
  end

  raise_sema_error("unknown field #{field_receiver_type}.#{expression.member}")
end

#infer_member_access_field_type(value, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 528

def infer_member_access_field_type(value, scopes)
  receiver_type = case value.receiver
  when AST::Identifier
    if value.receiver.name == "this"
      (binding = lookup_value("this", scopes)) ? binding.type : nil
    else
      (binding = lookup_value(value.receiver.name, scopes)) ? binding.type : nil
    end
  end
  return nil unless receiver_type

  field_receiver = receiver_type_for_fields(receiver_type)
  field_receiver&.respond_to?(:fields) ? field_receiver.fields[value.member] : nil
end

#infer_member_handle_member(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1662

def infer_member_handle_member(expression)
  case expression.member
  when "name"
    @ctx.types.fetch("str")
  when "value"
    @ctx.types.fetch("int")
  else
    raise_sema_error("unknown member #{expression.member} of member_handle")
  end
end

#infer_method_receiver_type(receiver_expression, scopes:, member_name: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1314

def infer_method_receiver_type(receiver_expression, scopes:, member_name: nil)
  receiver_type = infer_expression(receiver_expression, scopes:)
  project_method_receiver_type(receiver_type, member_name:)
end

#infer_null_literal(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 200

def infer_null_literal(expression)
  return @null_type unless expression.type

  target_type = resolve_type_ref(expression.type)
  unless typed_null_target_type?(target_type)
    raise_sema_error("typed null requires pointer-like type, got #{target_type}")
  end

  Types::Null.new(target_type)
end

#infer_offsetof_type(type_ref, field_name, scopes: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 629

def infer_offsetof_type(type_ref, field_name, scopes: nil)
  type = resolve_type_ref(type_ref)
  unless layout_aggregate_type?(type)
    raise_sema_error("offset_of requires a struct, union, span, or str type, got #{type}")
  end

  field_type = type.field(field_name)
  return type if field_type

  if scopes
    binding = lookup_value(field_name, scopes)
    if binding && binding.storage_type.is_a?(Types::ReflectionHandleType) && binding.storage_type.name == "field_handle"
      return type
    end
  end

  raise_sema_error("unknown field #{type}.#{field_name}")
end

#infer_option_propagation(source_type, allow_void_success:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 541

def infer_option_propagation(source_type, allow_void_success:)
  success_type = let_else_success_type(source_type)
  raise_sema_error("propagation requires a non-void Option success type") if success_type == @ctx.types.fetch("void") && !allow_void_success

  context = current_return_context
  raise_sema_error("propagation is only allowed inside function and proc bodies") unless context
  raise_sema_error("propagation is not allowed inside defer blocks") unless context[:allow_return]

  return_type = context[:return_type]
  unless option_let_else_type?(return_type)
    raise_sema_error("propagation requires enclosing function/proc to return Option[_], got #{return_type}")
  end

  success_type
end

#infer_proc_expression(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 847

def infer_proc_expression(expression, scopes:, expected_type: nil)
  proc_type = resolve_type_ref(AST::ProcType.new(params: expression.params, return_type: expression.return_type))
  if expected_type && !proc_type_compatible?(proc_type, expected_type)
    raise_sema_error("proc expression expects #{proc_type}, got #{expected_type}")
  end

  proc_scopes = scopes.map { |scope| freeze_scope_bindings(scope) }
  proc_scope = {}
  expression.params.each do |param|
    ensure_non_reserved_primitive_name!(param.name, kind_label: "parameter", line: param.line, column: param.column)
    param_type = resolve_type_ref(param.type)
    validate_parameter_ref_type!(param_type, function_name: "proc", parameter_name: param.name, external: false)
    validate_parameter_proc_type!(param_type, function_name: "proc", parameter_name: param.name, external: false, foreign: false)
    proc_scope[param.name] = value_binding(name: param.name, type: param_type, mutable: false, kind: :param)
  end

  check_block(expression.body, scopes: proc_scopes + [proc_scope], return_type: proc_type.return_type, allow_return: true)
  proc_type
end

#infer_propagate_expression(operand, scopes:, allow_void_success: false) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 508

def infer_propagate_expression(operand, scopes:, allow_void_success: false)
  source_type = infer_expression(operand, scopes:)
  if result_let_else_type?(source_type)
    infer_result_propagation(source_type, allow_void_success:)
  elsif option_let_else_type?(source_type)
    infer_option_propagation(source_type, allow_void_success:)
  else
    raise_sema_error("propagation expects Result[T, E] or Option[T], got #{source_type}")
  end
end

#infer_receiver_type_substitutions(binding, receiver_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 6

def infer_receiver_type_substitutions(binding, receiver_type)
  declared_receiver_type = binding.declared_receiver_type
  return {} unless declared_receiver_type
  case declared_receiver_type
  when Types::Nullable
    unless receiver_type.is_a?(Types::Nullable)
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end

    infer_receiver_type_substitutions(
      binding.with(declared_receiver_type: declared_receiver_type.base),
      receiver_type.base,
    )
  when Types::StructInstance
    return {} unless declared_receiver_type.definition.is_a?(Types::GenericStructDefinition)

    unless receiver_type.is_a?(Types::StructInstance) && receiver_type.definition == declared_receiver_type.definition
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end

    declared_receiver_type.definition.type_params.zip(receiver_type.arguments).to_h
  when Types::VariantInstance
    return {} unless declared_receiver_type.definition.is_a?(Types::GenericVariantDefinition)

    unless receiver_type.is_a?(Types::VariantInstance) && receiver_type.definition == declared_receiver_type.definition
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end

    declared_receiver_type.definition.type_params.zip(receiver_type.arguments).to_h
  when Types::GenericInstance
    unless receiver_type.is_a?(Types::GenericInstance) && receiver_type.name == declared_receiver_type.name && receiver_type.arguments.length == declared_receiver_type.arguments.length
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end

    declared_receiver_type.arguments.zip(receiver_type.arguments).each_with_object({}) do |(declared_argument, actual_argument), substitutions|
      if declared_argument.is_a?(Types::TypeVar)
        substitutions[declared_argument.name] = actual_argument
      elsif declared_argument != actual_argument
        raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
      end
    end
  when Types::Span
    return {} unless receiver_type.is_a?(Types::Span)

    substitutions = {}
    if declared_receiver_type.element_type.is_a?(Types::TypeVar)
      substitutions[declared_receiver_type.element_type.name] = receiver_type.element_type
    elsif declared_receiver_type.element_type != receiver_type.element_type
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end
    substitutions
  when Types::Task
    return {} unless receiver_type.is_a?(Types::Task)

    substitutions = {}
    if declared_receiver_type.result_type.is_a?(Types::TypeVar)
      substitutions[declared_receiver_type.result_type.name] = receiver_type.result_type
    elsif declared_receiver_type.result_type != receiver_type.result_type
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end
    substitutions
  when Types::SoA
    return {} unless receiver_type.is_a?(Types::SoA)

    substitutions = {}
    if declared_receiver_type.element_type.is_a?(Types::TypeVar)
      substitutions[declared_receiver_type.element_type.name] = receiver_type.element_type
    elsif declared_receiver_type.element_type != receiver_type.element_type
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end
    substitutions
  when Types::Simd
    return {} unless receiver_type.is_a?(Types::Simd)

    substitutions = {}
    if declared_receiver_type.element_type.is_a?(Types::TypeVar)
      substitutions[declared_receiver_type.element_type.name] = receiver_type.element_type
    elsif declared_receiver_type.element_type != receiver_type.element_type
      raise_sema_error("cannot use method #{binding.name} with receiver #{receiver_type}")
    end
    substitutions
  else
    {}
  end
end

#infer_recovered_match_expression(expression, scopes:, expected_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 754

def infer_recovered_match_expression(expression, scopes:, expected_type:)
  arm_entries = expression.arms.map do |arm|
    arm_scopes = scopes
    if arm.binding_name
      ensure_non_reserved_primitive_name!(arm.binding_name, kind_label: "match binding", line: arm.binding_line, column: arm.binding_column)
      binding = value_binding(
        name: arm.binding_name,
        type: @error_type,
        mutable: false,
        kind: :local,
        id: @preassigned_local_binding_ids.fetch(arm.object_id),
      )
      arm_scopes = scopes + [{ arm.binding_name => binding }]
      record_declaration_binding(arm, binding)
    end
    [infer_match_expression_arm_value(arm, scopes: arm_scopes, expected_type:), arm.value]
  end

  match_expression_common_type(arm_entries, expected_type)
end

#infer_reference_value_type(handle_expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1300

def infer_reference_value_type(handle_expression, scopes:)
  handle_type = infer_expression(handle_expression, scopes:)
  return referenced_type(handle_type) if ref_type?(handle_type)

  pointee = pointee_type(handle_type)
  if pointee
    require_unsafe!("raw pointer dereference requires unsafe") unless own_type?(handle_type)

    return pointee
  end

  raise_sema_error("read expects ref[...] or ptr[...], got #{handle_type}")
end

#infer_result_propagation(source_type, allow_void_success:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 519

def infer_result_propagation(source_type, allow_void_success:)
  success_type = let_else_success_type(source_type)
  error_type = let_else_error_type(source_type)
  raise_sema_error("propagation requires a non-void Result success type") if success_type == @ctx.types.fetch("void") && !allow_void_success

  context = current_return_context
  raise_sema_error("propagation is only allowed inside function and proc bodies") unless context
  raise_sema_error("propagation is not allowed inside defer blocks") unless context[:allow_return]

  return_type = context[:return_type]
  unless result_let_else_type?(return_type)
    raise_sema_error("propagation requires enclosing function/proc to return Result[_, #{error_type}], got #{return_type}")
  end

  return_error_type = let_else_error_type(return_type)
  unless return_error_type == error_type
    raise_sema_error("propagation error type #{error_type} must match enclosing Result error type #{return_error_type}")
  end

  success_type
end

#infer_ro_addr_source_type(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1269

def infer_ro_addr_source_type(expression, scopes:)
  raise_sema_error("const_ptr_of requires a safe lvalue source") unless safe_reference_source_expression?(expression, scopes:)

  source_type = infer_expression(expression, scopes:)
  if contains_ref_type?(source_type)
    unless (source_type.is_a?(Types::Struct) || source_type.is_a?(Types::StructInstance)) && source_type.lifetime_params&.any?
      raise_sema_error("const_ptr_of cannot target ref values")
    end
  end

  source_type
end

#infer_simple_local_type(value, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 501

def infer_simple_local_type(value, scopes)
  case value
  when AST::Call
    infer_call_return_type(value, scopes)
  when AST::MemberAccess
    infer_member_access_field_type(value, scopes)
  when AST::Identifier
    (binding = lookup_value(value.name, scopes)) ? binding.type : nil
  when AST::IntegerLiteral
    @ctx.types["int"]
  when AST::FloatLiteral
    @ctx.types["float"] || @ctx.types["double"]
  when AST::CharLiteral
    @ctx.types["ubyte"]
  when AST::BooleanLiteral
    @ctx.types["bool"]
  when AST::StringLiteral
    @ctx.types["str"]
  when AST::PrefixCast
    if value.target_type.respond_to?(:name)
      @ctx.types[value.target_type.name] || @ctx.types["int"]
    else
      @ctx.types["int"]
    end
  end
end

#infer_string_match_expression(expression, scrutinee_type, scopes:, expected_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 791

def infer_string_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  arm_entries = []
  each_string_match_arm(expression, scrutinee_type, scopes:) do |arm|
    arm_entries << [infer_match_expression_arm_value(arm, scopes:, expected_type:), arm.value]
  end
  match_expression_common_type(arm_entries, expected_type)
end

#infer_tuple_match_expression(expression, scrutinee_type, scopes:, expected_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 799

def infer_tuple_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  arm_entries = []
  each_tuple_match_arm(expression, scrutinee_type, scopes:) do |arm|
    arm_entries << [infer_match_expression_arm_value(arm, scopes:, expected_type:), arm.value]
  end
  match_expression_common_type(arm_entries, expected_type)
end

#infer_unary(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 473

def infer_unary(expression, scopes:, expected_type: nil)
  return infer_propagate_expression(expression.operand, scopes:) if expression.operator == "?"

  operand_type = infer_expression(expression.operand, scopes:, expected_type:)

  case expression.operator
  when "not"
    ensure_assignable!(operand_type, @ctx.types.fetch("bool"), "operator not requires bool, got #{operand_type}")
    @ctx.types.fetch("bool")
  when "+", "-"
    raise_sema_error("operator #{expression.operator} requires a numeric operand, got #{operand_type}") unless operand_type.numeric?

    if expression.operator == "-" && operand_type.integer?
      ct_value = evaluate_compile_time_const_value(expression, scopes:)
      if ct_value.is_a?(Integer) && !value_fits_integer_type?(ct_value, operand_type)
        raise_sema_error("negated value #{ct_value} does not fit in type #{operand_type}", expression)
      end
    end

    operand_type
  when "~"
    if simd_type?(operand_type)
      raise_sema_error("operator ~ on simd requires integer element type, got #{operand_type.element_type}") unless operand_type.element_type.integer?
      return operand_type
    end
    raise_sema_error("operator ~ requires an integer or flags operand, got #{operand_type}") unless bitwise_type?(operand_type)

    operand_type
  when "out", "in", "inout"
    raise_sema_error("#{expression.operator} is only allowed for foreign call arguments")
  else
    raise_sema_error("unsupported unary operator #{expression.operator}")
  end
end

#infer_unsafe_expression(expression, scopes:, expected_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 255

def infer_unsafe_expression(expression, scopes:, expected_type: nil)
  @unsafe_statement_lines << expression.line
  begin
    with_unsafe do
      infer_expression(expression.expression, scopes:, expected_type:)
    end
  ensure
    @unsafe_statement_lines.pop
  end
end

#infer_variant_match_expression(expression, scrutinee_type, scopes:, expected_type:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 807

def infer_variant_match_expression(expression, scrutinee_type, scopes:, expected_type:)
  arm_entries = []
  each_variant_match_arm(expression, scrutinee_type, scopes:) do |arm, arm_scopes|
    arm_entries << [infer_match_expression_arm_value(arm, scopes: arm_scopes, expected_type:), arm.value]
  end
  match_expression_common_type(arm_entries, expected_type)
end

#inline_for_element_type(element) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1307

def inline_for_element_type(element)
  if element.is_a?(Types::FieldHandle)
    builtin_field_handle_type
  elsif element.is_a?(Types::CallableHandle)
    builtin_callable_handle_type
  elsif element.is_a?(Types::AttributeHandle)
    builtin_attribute_handle_type
  elsif element.is_a?(Types::MemberHandle)
    builtin_member_handle_type
  elsif element.is_a?(Types::StructHandle)
    builtin_struct_handle_type
  else
    @ctx.types.fetch("int")
  end
end

#inline_foreign_call_requires_hoisting_message(foreign_call, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1122

def inline_foreign_call_requires_hoisting_message(foreign_call, scopes:)
  binding = foreign_call[:binding]
  call = foreign_call[:call]
  reference_counts = foreign_mapping_reference_counts(foreign_mapping_expression(binding.ast))

  binding.ast.params.each_with_index do |param_ast, index|
    public_alias = param_ast.boundary_type ? foreign_mapping_public_alias_name(param_ast.name) : nil
    total_references = reference_counts.fetch(param_ast.name, 0)
    total_references += reference_counts.fetch(public_alias, 0) if public_alias
    next if total_references <= 1 || simple_foreign_argument_expression?(call.arguments.fetch(index).value)

    return inline_foreign_hoisting_message(binding.name, param_ast.name, reason: "is referenced multiple times in its mapping")
  end

  binding.ast.params.each_with_index do |param_ast, index|
    parameter = binding.type.params.fetch(index)
    argument_expression = call.arguments.fetch(index).value
    next unless automatic_foreign_cstr_temp_needed?(parameter, argument_expression, scopes:) || automatic_foreign_cstr_list_temp_needed?(parameter)

    return inline_foreign_hoisting_message(binding.name, param_ast.name, reason: "needs temporary foreign text storage")
  end

  nil
end

#inline_foreign_hoisting_message(binding_name, parameter_name, reason:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1147

def inline_foreign_hoisting_message(binding_name, parameter_name, reason:)
  "foreign call #{binding_name} cannot be used inline because #{parameter_name} #{reason}; use it as a statement, local initializer, assignment, or return expression"
end

#inside_async_function? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 86

def inside_async_function?
  @async_function_depth.positive?
end

#inside_loop? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 90

def inside_loop?
  @loop_depth.positive?
end

#install_builtin_attributes ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 110

def install_builtin_attributes
  BUILTIN_ATTRIBUTE_NAMES.each do |name|
    @ctx.attributes[name] = MilkTea.builtin_attribute_binding(name, @ctx.types)
  end
end

#install_builtin_types ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 33

def install_builtin_types
  INSTALLABLE_BUILTIN_TYPE_NAMES.each do |name|
    @ctx.types[name] = case name
    when "str"
      Types::Registry.string_view
    when "Subscription"
      builtin_subscription_type
    when "EventError"
      builtin_event_error_type
    when "struct_handle"
      builtin_struct_handle_type
    when "field_handle"
      builtin_field_handle_type
    when "callable_handle"
      builtin_callable_handle_type
    when "attribute_handle"
      builtin_attribute_handle_type
    when "member_handle"
      builtin_member_handle_type
    when "type"
      builtin_type_meta_type
    when "vec2"
      Types::Vector.new("vec2", element_type: Types::BUILTIN_VECTOR_ELEMENT, width: 2)
    when "vec3"
      Types::Vector.new("vec3", element_type: Types::BUILTIN_VECTOR_ELEMENT, width: 3)
    when "vec4"
      Types::Vector.new("vec4", element_type: Types::BUILTIN_VECTOR_ELEMENT, width: 4)
    when "ivec2"
      Types::Vector.new("ivec2", element_type: Types::BUILTIN_IVECTOR_ELEMENT, width: 2)
    when "ivec3"
      Types::Vector.new("ivec3", element_type: Types::BUILTIN_IVECTOR_ELEMENT, width: 3)
    when "ivec4"
      Types::Vector.new("ivec4", element_type: Types::BUILTIN_IVECTOR_ELEMENT, width: 4)
    when "mat3"
      Types::Matrix.new("mat3", dim: 3)
    when "mat4"
      Types::Matrix.new("mat4", dim: 4)
    when "quat"
      Types::Quaternion.new("quat")
    else
      Types::Registry.primitive(name)
    end
  end
end

#install_fallback_builtin_type(module_path) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 193

def install_fallback_builtin_type(module_path)
  case module_path
  when "std.option"
    @ctx.types["Option"] = Types::BUILTIN_OPTION_TYPE unless @ctx.types.key?("Option")
  when "std.result"
    @ctx.types["Result"] = Types::BUILTIN_RESULT_TYPE unless @ctx.types.key?("Result")
  end
end

#install_imports ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 142

def install_imports
  @ctx.ast.imports.each do |import|
    with_error_node(import) do
      alias_name = import.alias_name || import.path.parts.last
      ensure_non_reserved_import_alias_name!(alias_name, kind_label: "import alias", line: import.line, column: import.column)
      raise_sema_error("duplicate import alias #{alias_name}") if @ctx.imports.key?(alias_name)

      module_binding = @ctx.imported_modules[import.path.to_s]
      next if @allow_missing_imports && module_binding.nil?
      raise_sema_error("unknown import #{import.path}") unless module_binding

      @ctx.imports[alias_name] = module_binding
    end
  end
end

#install_prelude_types ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 160

def install_prelude_types
  PRELUDE_MODULE_PATHS.each do |module_path|
    next if module_path == @ctx.module_name

    module_binding = @ctx.imported_modules[module_path]
    unless module_binding
      install_fallback_builtin_type(module_path)
      @ctx.imports[module_path] = empty_module_binding(module_path) unless @ctx.imports.key?(module_path)
      next
    end

    module_binding.types.each do |type_name, type|
      @ctx.types[type_name] = type unless @ctx.types.key?(type_name)
    end

    already_imported = @ctx.imports.any? { |_, existing_binding| existing_binding == module_binding }
    @ctx.imports[module_path] = module_binding unless @ctx.imports.key?(module_path) || already_imported
  end
end

#instantiate_function_binding(binding, type_arguments) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 204

def instantiate_function_binding(binding, type_arguments)
  if binding.type_params.empty?
    raise_sema_error("function #{binding.name} is not generic and cannot be specialized")
  end

  unless binding.type_params.length == type_arguments.length
    raise_sema_error("function #{binding.name} expects #{binding.type_params.length} type arguments, got #{type_arguments.length}")
  end

  if type_arguments.any? { |type_argument| contains_ref_type?(type_argument) }
    raise_sema_error("generic function #{binding.name} cannot be instantiated with ref types")
  end

  key = type_arguments.freeze
  return binding.instances.fetch(key) if binding.instances.key?(key)

  substitutions = binding.type_params.zip(type_arguments).to_h
  validate_function_type_param_constraints!(binding, substitutions)
  type = substitute_type(binding.type, substitutions)
  body_params = binding.body_params.map { |param| substitute_value_binding(param, substitutions) }
  validate_specialized_function_binding!(binding.name, type, body_params)

  instance = FunctionBinding.new(
    name: binding.name,
    type:,
    body_params:,
    body_return_type: substitute_type(binding.body_return_type, substitutions),
    ast: binding.ast,
    external: binding.external,
    async: binding.async,
    type_params: [].freeze,
    type_param_constraints: {}.freeze,
    instances: {},
    type_arguments: key,
    owner: binding.owner,
    specialization_owner: @current_specialization_owner || (binding.owner == self ? nil : self),
    type_substitutions: substitutions.freeze,
    declared_receiver_type: binding.declared_receiver_type ? substitute_type(binding.declared_receiver_type, substitutions) : nil,
  )
  binding.instances[key] = instance
end

#instantiate_function_binding_with_receiver(binding, explicit_type_arguments, receiver_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 176

def instantiate_function_binding_with_receiver(binding, explicit_type_arguments, receiver_type: nil)
  if binding.type_params.empty?
    raise_sema_error("function #{binding.name} is not generic and cannot be specialized")
  end

  receiver_substitutions = infer_receiver_type_substitutions(binding, receiver_type)
  remaining_type_params = binding.type_params.reject { |name| receiver_substitutions.key?(name) }
  unless remaining_type_params.length == explicit_type_arguments.length
    raise_sema_error("function #{binding.name} expects #{remaining_type_params.length} type arguments, got #{explicit_type_arguments.length}")
  end

  substitutions = receiver_substitutions.dup
  remaining_type_params.zip(explicit_type_arguments).each do |name, type_argument|
    raise_sema_error("generic function #{binding.name} cannot be instantiated with ref types") if contains_ref_type?(type_argument)

    substitutions[name] = type_argument
  end

  type_arguments = binding.type_params.map do |name|
    inferred = substitutions[name]
    raise_sema_error("cannot infer type argument #{name} for function #{binding.name}") unless inferred

    inferred
  end

  instantiate_function_binding(binding, type_arguments)
end

#integer_constant_fits_in_char?(expression, scopes) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 143

def integer_constant_fits_in_char?(expression, scopes)
  value = evaluate_compile_time_const_value(expression, scopes:)
  return true unless value.is_a?(Integer)

  value >= 0 && value <= 255
end

#integer_literal_expression?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 909

def integer_literal_expression?(expression)
  expression.is_a?(AST::IntegerLiteral)
end

#integer_suffix_type(lexeme) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 292

def integer_suffix_type(lexeme)
  INTEGER_SUFFIX_TYPES.sort_by { |k, _| -k.length }.find { |suffix, _| lexeme.end_with?(suffix) }&.last
end

#integer_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 839

def integer_type?(type)
  type.is_a?(Types::Primitive) && type.integer?
end

#integer_type_argument?(argument) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 786

def integer_type_argument?(argument)
  argument.is_a?(Types::LiteralTypeArg) && argument.value.is_a?(Integer)
end

#interface_implementation_key(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 158

def interface_implementation_key(type)
  return type.definition if type.is_a?(Types::StructInstance)

  type
end

#iterator_loop_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 876

def iterator_loop_type(type)
  type = referenced_type(type) if ref_type?(type)
  iter_method = lookup_method(type, "iter")
  return nil unless iter_method

  iter_method = instantiate_function_binding_with_receiver(iter_method, [], receiver_type: type) if iter_method.type_params.any?

  unless iter_method.type.params.empty?
    raise_sema_error("for iterator #{type}.iter expects 0 arguments")
  end
  if iter_method.type.receiver_editable
    raise_sema_error("for iterator #{type}.iter cannot be an editable method")
  end

  iterator_type = iter_method.type.return_type
  next_method = lookup_method(iterator_type, "next")
  raise_sema_error("for iterator #{iterator_type} must define next()") unless next_method
  next_method = instantiate_function_binding_with_receiver(next_method, [], receiver_type: iterator_type) if next_method.type_params.any?
  unless next_method.type.params.empty?
    raise_sema_error("for iterator #{iterator_type}.next expects 0 arguments")
  end

  next_type = next_method.type.return_type
  if next_type.is_a?(Types::Nullable) && typed_null_target_type?(next_type.base)
    return next_type.base
  end

  if next_type == @ctx.types.fetch("bool")
    current_method = lookup_method(iterator_type, "current")
    raise_sema_error("for iterator #{iterator_type} must define current() when next() returns bool") unless current_method
    current_method = instantiate_function_binding_with_receiver(current_method, [], receiver_type: iterator_type) if current_method.type_params.any?
    unless current_method.type.params.empty?
      raise_sema_error("for iterator #{iterator_type}.current expects 0 arguments")
    end
    raise_sema_error("for iterator #{iterator_type}.current cannot return void") if current_method.type.return_type == @ctx.types.fetch("void")

    return current_method.type.return_type
  end

  raise_sema_error("for iterator #{iterator_type}.next must return bool or a nullable pointer-like item, got #{next_type}")
end

#last_ast_line(statements) ⇒ Object

Returns the highest line number across a list of AST statement nodes, recursing into nested bodies (if/else/match/while/for/defer/unsafe).



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 367

def last_ast_line(statements)
  return nil if statements.nil? || statements.empty?

  statements.filter_map do |stmt|
    case stmt
    when AST::IfStmt
      branch_lines = stmt.branches.filter_map { |b| last_ast_line(b.body) }
      else_lines = last_ast_line(stmt.else_body)
      [stmt.line, *branch_lines, else_lines].compact.max
    when AST::WhileStmt, AST::ForStmt, AST::UnsafeStmt, AST::ErrorBlockStmt
      [stmt.line, last_ast_line(stmt.body)].compact.max
    when AST::MatchStmt
      arm_lines = stmt.arms.filter_map do |arm|
        if arm.respond_to?(:body)
          last_ast_line(arm.body)
        elsif arm.respond_to?(:value)
          arm.value.line
        end
      end
      [stmt.line, *arm_lines].compact.max
    when AST::DeferStmt
      [stmt.line, last_ast_line(stmt.body)].compact.max
    when AST::WhenStmt
      branch_lines = stmt.branches.filter_map { |b| last_ast_line(b.body) }
      else_lines = last_ast_line(stmt.else_body)
      [stmt.line, *branch_lines, else_lines].compact.max
    else
      stmt.line
    end
  end.compact.max
end

#layout_aggregate_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 693

def layout_aggregate_type?(type)
  type.respond_to?(:field) && !type.is_a?(Types::Opaque) && !type.is_a?(Types::EnumBase)
end

#let_else_discard_binding_syntax?(statement) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 777

def let_else_discard_binding_syntax?(statement)
  statement.is_a?(AST::LocalDecl) && (statement.else_body || statement.recovered_else) && statement.name == "_"
end

#let_else_error_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 794

def let_else_error_type(type)
  return @error_type if error_type?(type)
  return unless result_let_else_type?(type)

  type.arm("failure").fetch("error")
end

#let_else_source_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 781

def let_else_source_type?(type)
  type.is_a?(Types::Nullable) || result_let_else_type?(type) || option_let_else_type?(type)
end

#let_else_success_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 785

def let_else_success_type(type)
  return @error_type if error_type?(type)
  return type.base if type.is_a?(Types::Nullable)
  return type.arm("some").fetch("value") if option_let_else_type?(type)
  return unless result_let_else_type?(type)

  type.arm("success").fetch("value")
end

#levenshtein(s, t) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 293

def levenshtein(s, t)
  m = s.length
  n = t.length
  return m if n.zero?
  return n if m.zero?
  d = Array.new(m + 1) { Array.new(n + 1, 0) }
  (0..m).each { |i| d[i][0] = i }
  (0..n).each { |j| d[0][j] = j }
  (1..m).each do |i|
    (1..n).each do |j|
      cost = s[i - 1] == t[j - 1] ? 0 : 1
      d[i][j] = [d[i - 1][j] + 1, d[i][j - 1] + 1, d[i - 1][j - 1] + cost].min
    end
  end
  d[m][n]
end

#literal_type_argument_name_candidate?(type_ref) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 397

def literal_type_argument_name_candidate?(type_ref)
  type_ref.arguments.empty? && !type_ref.nullable
end

#lookup_local_binding(name, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1415

def lookup_local_binding(name, scopes)
  scopes.reverse_each do |scope|
    return scope[name] if scope.key?(name)
  end
  nil
end

#lookup_local_method_for_interface(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/interface_conformance.rb', line 39

def lookup_local_method_for_interface(receiver_type, name)
  dispatch_receiver_type = method_dispatch_receiver_type(receiver_type)

  method = @ctx.methods.fetch(receiver_type, {})[name]
  method ||= @ctx.methods.fetch(dispatch_receiver_type, {})[name] unless dispatch_receiver_type == receiver_type
  static_name = "static:#{name}"
  method ||= @ctx.methods.fetch(receiver_type, {})[static_name]
  method ||= @ctx.methods.fetch(dispatch_receiver_type, {})[static_name] unless dispatch_receiver_type == receiver_type
  method
end

#lookup_method(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 22

def lookup_method(receiver_type, name)
  method = lookup_method_local_or_imported(receiver_type, name)
  return method if method

  fallback_owner = specialization_lookup_owner
  return nil unless fallback_owner

  fallback_owner.lookup_method_local_or_imported(receiver_type, name)
end

#lookup_method_local_or_imported(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 43

def lookup_method_local_or_imported(receiver_type, name)
  dispatch_receiver_type = method_dispatch_receiver_type(receiver_type)

  method = @ctx.methods.fetch(receiver_type, {})[name]
  method ||= @ctx.methods.fetch(dispatch_receiver_type, {})[name] unless dispatch_receiver_type == receiver_type
  return method if method

  imported_candidates = []

  @ctx.imports.each_value do |module_binding|
    imported_method = module_binding.methods.fetch(receiver_type, {})[name]
    if imported_method.nil? && dispatch_receiver_type != receiver_type
      imported_method = module_binding.methods.fetch(dispatch_receiver_type, {})[name]
    end

    imported_candidates << [module_binding, imported_method] if imported_method
  end

  if imported_candidates.empty?
    owner_module = reachable_module_binding_for_type(receiver_type)
    return nil unless owner_module

    return module_binding_method(owner_module, receiver_type, dispatch_receiver_type, name)
  end

  if imported_candidates.length > 1
    modules = imported_candidates.map { |module_binding, _binding| module_binding.name }.join(", ")
    display_name = name.delete_prefix("static:")
    raise_sema_error("ambiguous imported method #{receiver_type}.#{display_name}; found in modules #{modules}")
  end

  imported_candidates.first.last
end

#lookup_static_method(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 32

def lookup_static_method(receiver_type, name)
  static_name = "static:#{name}"
  method = lookup_method_local_or_imported(receiver_type, static_name)
  return method if method

  fallback_owner = specialization_lookup_owner
  return nil unless fallback_owner

  fallback_owner.lookup_method_local_or_imported(receiver_type, static_name)
end

#lookup_value(name, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 14

def lookup_value(name, scopes)
  scopes.reverse_each do |scope|
    return scope[name] if scope.key?(name)
  end

  @ctx.top_level_values[name]
end

#mark_current_unsafe_required! ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 13

def mark_current_unsafe_required!
  current_line = @unsafe_statement_lines.last
  return unless current_line

  @required_unsafe_lines << current_line
end

#match_expression_common_type(arm_entries, expected_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 821

def match_expression_common_type(arm_entries, expected_type)
  return expected_type || @error_type if arm_entries.empty?

  if expected_type && arm_entries.all? { |type, expr| types_compatible?(type, expected_type, expression: expr) }
    return expected_type
  end

  common_type, common_expression = arm_entries.first
  arm_entries.drop(1).each do |type, expr|
    next if type == common_type

    merged_type = conditional_common_type(
      common_type,
      type,
      then_expression: common_expression,
      else_expression: expr,
    )
    raise_sema_error("match expression arms require compatible types, got #{common_type} and #{type}") unless merged_type

    common_type = merged_type
    common_expression = expr
  end

  common_type
end

#match_member_name(expression, enum_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 965

def match_member_name(expression, enum_type)
  return unless expression.is_a?(AST::MemberAccess)

  receiver_type = resolve_type_expression(expression.receiver)
  return unless receiver_type == enum_type
  return expression.member if enum_type.member(expression.member)

  nil
end

#matrix_op_result(operator, left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 277

def matrix_op_result(operator, left_type, right_type)
  if matrix_type?(left_type) && matrix_type?(right_type) && left_type.dim == right_type.dim
    return left_type if operator == "+" || operator == "-"
    return left_type if operator == "*"
  end

  if matrix_type?(left_type) && vector_type?(right_type) && left_type.dim == right_type.width && right_type.element_type == Types::BUILTIN_VECTOR_ELEMENT
    return Types::Vector.new(right_type.name, element_type: right_type.element_type, width: right_type.width) if operator == "*"
  end

  if matrix_type?(left_type) && right_type.numeric?
    return left_type if operator == "*" || operator == "/"
  end

  nil
end

#matrix_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 709

def matrix_type?(type)
  type.is_a?(Types::Matrix)
end

#merge_equality_cover(existing, new_cover) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 904

def merge_equality_cover(existing, new_cover)
  return new_cover unless existing
  merged = existing.dup
  new_cover.each do |field, members|
    merged[field] = (merged[field] || []) + members
  end
  merged
end

#merge_refinements(existing, incoming) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 55

def merge_refinements(existing, incoming)
  merged = existing.dup
  incoming.each do |name, refined_type|
    if merged.key?(name) && merged[name] != refined_type
      merged.delete(name)
    else
      merged[name] = refined_type
    end
  end

  merged
end

#merged_scope_bindings(scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 161

def merged_scope_bindings(scopes)
  scopes.each_with_object({}) do |scope, bindings|
    scope.each do |name, binding|
      next unless name.is_a?(String)

      bindings[name] = binding
    end
  end
end

#methods_receiver_type_argument_names!(type_ref) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1061

def methods_receiver_type_argument_names!(type_ref)
  names = type_ref.arguments.map do |argument|
    value = argument.value
    next unless value.is_a?(AST::TypeRef)
    next unless value.arguments.empty? && !value.nullable && value.name.parts.length == 1

    value.name.parts.first
  end

  raise_sema_error("extending target #{type_ref} must use the receiver type parameters directly") if names.any?(&:nil?)

  names
end

#module_binding_method(module_binding, receiver_type, dispatch_receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 77

def module_binding_method(module_binding, receiver_type, dispatch_receiver_type, name)
  method = module_binding.methods.fetch(receiver_type, {})[name]
  method ||= module_binding.methods.fetch(dispatch_receiver_type, {})[name] unless dispatch_receiver_type == receiver_type
  method
end

#module_name ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer.rb', line 136

def module_name
  @ctx.module_name
end

#noncopyable_event_storage_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 778

def noncopyable_event_storage_type?(type)
  event_type?(type) || event_carrier_type?(type)
end

#null_test_refinements(expression, truthy:, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 289

def null_test_refinements(expression, truthy:, scopes:)
  identifier_expression = nil
  if expression.left.is_a?(AST::Identifier) && expression.right.is_a?(AST::NullLiteral)
    identifier_expression = expression.left
  elsif expression.left.is_a?(AST::NullLiteral) && expression.right.is_a?(AST::Identifier)
    identifier_expression = expression.right
  else
    return {}
  end

  binding = lookup_value(identifier_expression.name, scopes)
  return {} unless binding&.storage_type.is_a?(Types::Nullable)

  null_result = expression.operator == "==" ? truthy : !truthy
  refined_type = null_result ? @null_type : binding.storage_type.base
  { identifier_expression.name => refined_type }
end

#nullable_candidate?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 327

def nullable_candidate?(type)
  return false if ref_type?(type)

  sized_layout_type?(type) || pointer_type?(type) || type.is_a?(Types::Nullable)
end

#option_let_else_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 801

def option_let_else_type?(type)
  return false unless type.is_a?(Types::Variant)

  some_fields = type.arm("some")
  none_fields = type.arm("none")
  some_fields && some_fields.length == 1 && some_fields.key?("value") &&
    none_fields && none_fields.empty?
end

#pointer_arithmetic_result(operator, left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 199

def pointer_arithmetic_result(operator, left_type, right_type)
  if pointer_type?(left_type) && integer_type?(right_type)
    require_unsafe!("pointer arithmetic requires unsafe") unless own_type?(left_type)

    return left_type if operator == "+" || operator == "-"
  end

  if operator == "+" && integer_type?(left_type) && pointer_type?(right_type)
    require_unsafe!("pointer arithmetic requires unsafe") unless own_type?(right_type)

    return right_type
  end

  nil
end

#pointer_cast?(source_type, target_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 307

def pointer_cast?(source_type, target_type)
  pointer_cast_type?(source_type) && pointer_cast_type?(target_type)
end

#pointer_cast_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 315

def pointer_cast_type?(type)
  return typed_null_target_type?(type.target_type) if type.is_a?(Types::Null)
  return true if type == @ctx.types.fetch("cstr")
  if type.is_a?(Types::Nullable)
    return true if function_pointer_type?(type.base)

    return pointer_type?(type.base)
  end

  return true if function_pointer_type?(type)

  pointer_type?(type)
end

#pointer_to(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 794

def pointer_to(type)
  Types.pointer_to(type)
end

#power_of_two?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 697

def power_of_two?(value)
  (value & (value - 1)).zero?
end

#preassign_local_binding_ids(statements) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 96

def preassign_local_binding_ids(statements)
  @preassigned_local_binding_ids = {}
  preassign_local_binding_ids_in_statements(statements || [])
end

#preassign_local_binding_ids_in_expression(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 170

def preassign_local_binding_ids_in_expression(expression)
  case expression
  when nil, AST::Identifier, AST::IntegerLiteral, AST::FloatLiteral, AST::StringLiteral,
       AST::BooleanLiteral, AST::NullLiteral, AST::SizeofExpr, AST::AlignofExpr,
       AST::OffsetofExpr, AST::ErrorExpr
    nil
  when AST::MemberAccess
    preassign_local_binding_ids_in_expression(expression.receiver)
  when AST::IndexAccess
    preassign_local_binding_ids_in_expression(expression.receiver)
    preassign_local_binding_ids_in_expression(expression.index)
  when AST::Specialization, AST::Call
    preassign_local_binding_ids_in_expression(expression.callee)
    expression.arguments.each { |argument| preassign_local_binding_ids_in_expression(argument.value) }
  when AST::UnaryOp
    preassign_local_binding_ids_in_expression(expression.operand)
  when AST::BinaryOp
    preassign_local_binding_ids_in_expression(expression.left)
    preassign_local_binding_ids_in_expression(expression.right)
  when AST::RangeExpr
    preassign_local_binding_ids_in_expression(expression.start_expr)
    preassign_local_binding_ids_in_expression(expression.end_expr)
  when AST::IfExpr
    preassign_local_binding_ids_in_expression(expression.condition)
    preassign_local_binding_ids_in_expression(expression.then_expression)
    preassign_local_binding_ids_in_expression(expression.else_expression)
  when AST::MatchExpr
    preassign_local_binding_ids_in_expression(expression.expression)
    expression.arms.each do |arm|
      preassign_local_binding_ids_in_expression(arm.pattern)
      @preassigned_local_binding_ids[arm.object_id] ||= allocate_binding_id if arm.binding_name
      preassign_local_binding_ids_in_expression(if arm.respond_to?(:value) then arm.value else arm.body end)
    end
  when AST::UnsafeExpr
    preassign_local_binding_ids_in_expression(expression.expression)
  when AST::PrefixCast
    preassign_local_binding_ids_in_expression(expression.expression)
  when AST::AwaitExpr
    preassign_local_binding_ids_in_expression(expression.expression)
  when AST::FormatString
    expression.parts.each do |part|
      preassign_local_binding_ids_in_expression(part.expression) if part.is_a?(AST::FormatExprPart)
    end
  when AST::ProcExpr
    preassign_local_binding_ids_in_statements(expression.body)
  end
end

#preassign_local_binding_ids_in_statements(statements) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 101

def preassign_local_binding_ids_in_statements(statements)
  statements.each do |statement|
    case statement
    when AST::ErrorBlockStmt
      preassign_local_binding_ids_in_expression(statement.header_expression) if statement.header_expression
      Array(statement.header_iterables).each { |iterable| preassign_local_binding_ids_in_expression(iterable) }
      Array(statement.header_bindings).each do |binding|
        @preassigned_local_binding_ids[binding.object_id] ||= allocate_binding_id
      end if statement.header_type == :for
      preassign_local_binding_ids_in_statements(statement.body || [])
    when AST::LocalDecl
      @preassigned_local_binding_ids[statement.object_id] ||= allocate_binding_id
      preassign_local_binding_ids_in_expression(statement.value) if statement.value
      if statement.else_binding && (statement.else_body || statement.recovered_else)
        @preassigned_local_binding_ids[statement.else_binding.object_id] ||= allocate_binding_id
      end
      preassign_local_binding_ids_in_statements(statement.else_body || [])
    when AST::Assignment
      preassign_local_binding_ids_in_expression(statement.target)
      preassign_local_binding_ids_in_expression(statement.value)
    when AST::IfStmt
      statement.branches.each do |branch|
        preassign_local_binding_ids_in_expression(branch.condition)
        preassign_local_binding_ids_in_statements(branch.body || [])
      end
      preassign_local_binding_ids_in_statements(statement.else_body || [])
    when AST::MatchStmt
      preassign_local_binding_ids_in_expression(statement.expression)
      statement.arms.each do |arm|
        preassign_local_binding_ids_in_expression(arm.pattern)
        @preassigned_local_binding_ids[arm.object_id] ||= allocate_binding_id if arm.binding_name

        # Preassign binding IDs for struct pattern bindings
        if arm.pattern.is_a?(AST::Call) && !arm.pattern.arguments.empty?
          arm.pattern.arguments.each do |arg|
            next if arg.name
            next unless arg.value.is_a?(AST::Identifier)

            @preassigned_local_binding_ids[arg.object_id] ||= allocate_binding_id
          end
        end

        preassign_local_binding_ids_in_statements(if arm.respond_to?(:body) then (arm.body || []) else [arm.value].compact end)
      end
    when AST::UnsafeStmt
      preassign_local_binding_ids_in_statements(statement.body || [])
    when AST::WhileStmt
      preassign_local_binding_ids_in_expression(statement.condition)
      preassign_local_binding_ids_in_statements(statement.body || [])
    when AST::ForStmt
      statement.bindings.each do |binding|
        @preassigned_local_binding_ids[binding.object_id] ||= allocate_binding_id
      end
      statement.iterables.each { |iterable| preassign_local_binding_ids_in_expression(iterable) }
      preassign_local_binding_ids_in_statements(statement.body || [])
    when AST::DeferStmt
      preassign_local_binding_ids_in_expression(statement.expression) if statement.expression
      preassign_local_binding_ids_in_statements(statement.body || []) if statement.body
    when AST::ReturnStmt
      preassign_local_binding_ids_in_expression(statement.value) if statement.value
    when AST::StaticAssert
      preassign_local_binding_ids_in_expression(statement.condition)
      preassign_local_binding_ids_in_expression(statement.message)
    when AST::ExpressionStmt
      preassign_local_binding_ids_in_expression(statement.expression)
    end
  end
end

#preassigned_local_binding_id_for(node) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1215

def preassigned_local_binding_id_for(node)
  @preassigned_local_binding_ids[node.object_id] ||= allocate_binding_id
end

#precheck_binding_resolution(statements, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 218

def precheck_binding_resolution(statements, scopes)
  declaration_binding_ids = {}
  identifier_binding_ids = {}

  initial_scope = {}
  scopes.each do |scope|
    scope.each do |name, binding|
      initial_scope[name] = binding.id if binding.respond_to?(:id) && binding.id
    end
  end

  walk_statements_for_precheck_resolution(
    statements || [],
    [initial_scope],
    declaration_binding_ids,
    identifier_binding_ids,
  )

  BindingResolution.new(
    identifier_binding_ids: identifier_binding_ids,
    declaration_binding_ids: declaration_binding_ids,
    mutating_argument_identifier_ids: {},
    editable_receiver_expression_ids: {},
    mutable_lvalue_argument_identifier_ids: {},
    binding_types: {},
  )
end

#proc_storage_supported_type?(type, visited = {}) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1153

def proc_storage_supported_type?(type, visited = {})
  return true unless contains_proc_type?(type)
  visitor = ProcStorageSupportedVisitor.new
  visitor.visit(type)
  visitor.result?
end

#proc_type_compatible?(actual_type, expected_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1092

def proc_type_compatible?(actual_type, expected_type)
  return true unless expected_type
  if proc_type?(expected_type)
    return true if expected_type.is_a?(Types::Proc) && actual_type.is_a?(Types::Proc) &&
      contains_type_var?(expected_type)
    return actual_type == expected_type
  end

  false
end

#project_field_receiver_type(receiver_type, require_mutable_pointer: false) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1324

def project_field_receiver_type(receiver_type, require_mutable_pointer: false)
  return referenced_type(receiver_type) if ref_type?(receiver_type)
  return receiver_type unless pointer_type?(receiver_type)

  require_unsafe!("raw pointer dereference requires unsafe") unless own_type?(receiver_type)
  if require_mutable_pointer && const_pointer_type?(receiver_type)
    raise_sema_error("cannot assign through read-only raw pointer #{receiver_type}")
  end

  pointee_type(receiver_type)
end

#project_method_receiver_type(receiver_type, member_name: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1336

def project_method_receiver_type(receiver_type, member_name: nil)
  receiver_type = referenced_type(receiver_type) if ref_type?(receiver_type)
  return receiver_type unless pointer_type?(receiver_type)

  return receiver_type if member_name && lookup_method(receiver_type, member_name)

  require_unsafe!("raw pointer dereference requires unsafe") unless own_type?(receiver_type)

  pointee_type(receiver_type)
end

#propagating_expected_type(operator, expected_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 913

def propagating_expected_type(operator, expected_type)
  case operator
  when "+", "-", "*", "/", "%", "<<", ">>"
    return expected_type if expected_type.is_a?(Types::Primitive) && expected_type.numeric?
  when "|", "&", "^"
    return expected_type if expected_type.is_a?(Types::Primitive) && expected_type.integer?
    return expected_type if expected_type.is_a?(Types::Flags)
  end

  nil
end

#qualified_attribute_name(binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 35

def qualified_attribute_name(binding)
  binding.module_name ? "#{binding.module_name}.#{binding.name}" : binding.name
end

#quat_vec4_compatible?(a, b) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 60

def quat_vec4_compatible?(a, b)
  (a.is_a?(Types::Quaternion) && b.is_a?(Types::Vector) && b.width == 4 && b.element_type.name == "float") ||
    (b.is_a?(Types::Quaternion) && a.is_a?(Types::Vector) && a.width == 4 && a.element_type.name == "float")
end

#quaternion_op_result(operator, left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 294

def quaternion_op_result(operator, left_type, right_type)
  if quaternion_type?(left_type) && quaternion_type?(right_type)
    return left_type if operator == "+" || operator == "-"
    return left_type if operator == "*"
  end

  if quaternion_type?(left_type) && vector_type?(right_type) && right_type.width == 3 && right_type.element_type == Types::BUILTIN_VECTOR_ELEMENT
    return right_type if operator == "*"
  end

  nil
end

#quaternion_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 713

def quaternion_type?(type)
  type.is_a?(Types::Quaternion)
end

#raise_sema_error(message, node = nil, line: nil, column: nil, length: nil, suggestion: nil) ⇒ Object

Raises:



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 503

def raise_sema_error(message, node = nil, line: nil, column: nil, length: nil, suggestion: nil)
  target = node || current_error_node
  line ||= source_line(target)
  column ||= source_column(target)
  length ||= source_length(target)
  raise SemanticError.new(message, line:, column:, length:, path: @path, suggestion:)
end

#raw_module? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1351

def raw_module?
  @ctx.module_kind == :raw_module
end

#reachable_module_binding_for_type(receiver_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 83

def reachable_module_binding_for_type(receiver_type)
  module_name = receiver_type_module_name(receiver_type)
  return nil unless module_name
  return nil if module_name == @ctx.module_name

  find_reachable_imported_module(module_name)
end

#read_call?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1347

def read_call?(expression)
  expression.is_a?(AST::Call) && expression.callee.is_a?(AST::Identifier) && expression.callee.name == "read"
end

#receiver_type_for_fields(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 591

def receiver_type_for_fields(type)
  type = type.base while type.is_a?(Types::Nullable)
  type = type.arguments.first if type.respond_to?(:name) && type.name == 'ref' && type.respond_to?(:arguments) && type.arguments&.length == 1
  type = type.definition if type.respond_to?(:definition)
  type
end

#receiver_type_module_name(receiver_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 91

def receiver_type_module_name(receiver_type)
  return receiver_type_module_name(receiver_type.base) if receiver_type.is_a?(Types::Nullable)
  return receiver_type.module_name if receiver_type.respond_to?(:module_name)

  nil
end

#record_callable_value_expression_site(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1400

def record_callable_value_expression_site(expression)
  case expression
  when AST::Identifier
    record_callable_value_identifier_site(expression)
  when AST::MemberAccess
    record_callable_value_member_access_site(expression)
  end
end

#record_callable_value_identifier_site(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1393

def record_callable_value_identifier_site(expression)
  return unless expression.is_a?(AST::Identifier)
  return unless expression.line && expression.column

  @callable_value_identifier_sites[[expression.line, expression.column]] = true
end

#record_callable_value_member_access_site(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1409

def record_callable_value_member_access_site(expression)
  return unless expression.is_a?(AST::MemberAccess)
  return unless expression.receiver.is_a?(AST::Identifier)
  return unless expression.receiver.line && expression.receiver.column

  @callable_value_member_access_sites[
    [expression.receiver.name, expression.receiver.line, expression.receiver.column, expression.member]
  ] = true
end

#record_declaration_binding(node, binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1419

def record_declaration_binding(node, binding)
  return unless node
  return unless binding&.id

  @declaration_binding_ids[node.object_id] = binding.id
end

#record_editable_receiver_expression(receiver) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1473

def record_editable_receiver_expression(receiver)
  return unless receiver

  @editable_receiver_expression_ids[receiver.object_id] = true
end

#record_identifier_binding(expression, binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1386

def record_identifier_binding(expression, binding)
  return unless expression.is_a?(AST::Identifier)
  return unless binding&.id

  @identifier_binding_ids[expression.object_id] = binding.id
end

#record_local_completion_snapshot(line, column, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 142

def record_local_completion_snapshot(line, column, scopes)
  return if @active_local_completion_stack.empty?
  return if line.nil?

  snapshot = LocalCompletionSnapshot.new(
    line:,
    column: (column || 0),
    bindings: merged_scope_bindings(scopes).freeze,
  )

  snapshots = @active_local_completion_stack.last[:snapshots]
  prev = snapshots.last
  if prev && prev.line == snapshot.line && prev.column == snapshot.column
    snapshots[-1] = snapshot
  else
    snapshots << snapshot
  end
end

#record_mutable_lvalue_argument_identifier(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1479

def record_mutable_lvalue_argument_identifier(expression)
  return unless expression.is_a?(AST::Identifier)

  @mutable_lvalue_argument_identifier_ids[expression.object_id] = true
end

#record_mutating_argument_identifier(argument, parameter) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 817

def record_mutating_argument_identifier(argument, parameter)
  return unless %i[out inout].include?(parameter.passing_mode)
  return unless argument.value.is_a?(AST::Identifier)

  @mutating_argument_identifier_ids[argument.value.object_id] = true
end

#recovered_for_statement(statement) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 279

def recovered_for_statement(statement)
  AST::ForStmt.new(
    bindings: Array(statement.header_bindings),
    iterables: Array(statement.header_iterables),
    body: statement.body,
    line: statement.line,
    column: statement.column,
  )
end

#ref_to_pointer_cast?(source_type, target_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 311

def ref_to_pointer_cast?(source_type, target_type)
  ref_type?(source_type) && pointer_cast_type?(target_type)
end

#ref_types_compatible?(actual_type, expected_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 54

def ref_types_compatible?(actual_type, expected_type)
  return false unless ref_type?(actual_type) && ref_type?(expected_type)

  referenced_type(actual_type) == referenced_type(expected_type)
end

#reflection_identifier_name(expression, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1596

def reflection_identifier_name(expression, context:)
  raise_sema_error("#{context} expects an identifier argument") unless expression.is_a?(AST::Identifier)

  expression.name
end

#register_nested_struct_types(parent_decl, parent_name: parent_decl.name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 848

def register_nested_struct_types(parent_decl, parent_name: parent_decl.name)
  parent_decl.nested_types.each do |nested|
    qualified_name = "#{parent_name}.#{nested.name}"
    ensure_available_type_name!(qualified_name)
    nested_c_name = if @ctx.module_name && !raw_module?
      "#{@ctx.module_name.to_s.tr('.', '_')}_#{qualified_name.tr('.', '_')}"
    else
      qualified_name.tr('.', '_')
    end
    if nested.type_params.empty?
      @ctx.types[qualified_name] = Types::Struct.new(nested.name, module_name: @ctx.module_name, external: raw_module?, packed: nested.packed, alignment: nested.alignment, linkage_name: nested_c_name, lifetime_params: nested.lifetime_params)
    else
      @ctx.types[qualified_name] = Types::GenericStructDefinition.new(nested.name, nested.type_params.map(&:name), module_name: @ctx.module_name, external: raw_module?, packed: nested.packed, alignment: nested.alignment, linkage_name: nested_c_name, lifetime_params: nested.lifetime_params)
    end
    register_nested_struct_types(nested, parent_name: qualified_name)
  end
end

#reinterpretable_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 661

def reinterpretable_type?(type)
  return false if array_type?(type)
  return false if type.is_a?(Types::Primitive) && type.void?

  sized_layout_type?(type)
end

#reject_foreign_nullable_value_type!(type, function_name:, parameter_name:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 20

def reject_foreign_nullable_value_type!(type, function_name:, parameter_name:)
  return unless type.is_a?(Types::Nullable)
  return if foreign_boundary_nullable_pointer_like_base?(type.base)

  location = parameter_name ? "parameter #{parameter_name}" : "return type"
  raise_sema_error("#{location} of foreign/external function #{function_name} cannot use nullable value type #{type}; nullable at an FFI boundary is only supported for pointer-like types (use ptr[...]? or pass an explicit struct)")
end

#require_unsafe!(message, line: nil, column: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 20

def require_unsafe!(message, line: nil, column: nil)
  if unsafe_context?
    mark_current_unsafe_required!
    return
  end

  suggestion = "wrap in an unsafe block: `unsafe: <expression>`"
  if line || column
    raise SemanticError.new(message, line:, column:, path: @path, suggestion:)
  end

  raise_sema_error(message, suggestion:)
end

#resolve_adapt_interface(type_arg) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 1006

def resolve_adapt_interface(type_arg)
  parts = type_arg.name.parts
  type_args = type_arg.arguments.map { |a| a.value }
  interface_ref = AST::QualifiedName.new(parts:, type_arguments: type_args)
  resolve_interface_ref(interface_ref)
end

#resolve_aggregate_fields ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 447

def resolve_aggregate_fields
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      next unless decl.is_a?(AST::StructDecl) || decl.is_a?(AST::UnionDecl)

      struct_type = @ctx.types.fetch(decl.name)
      struct_type.ast_declaration = decl if struct_type.respond_to?(:ast_declaration=)
      type_params = if struct_type.is_a?(Types::GenericStructDefinition)
        seen = {}
        struct_type.type_params.each_with_object({}) do |name, params|
          raise_sema_error("duplicate type parameter #{decl.name}[#{name}]") if seen.key?(name)

          seen[name] = true
          params[name] = Types::TypeVar.new(name)
        end
      else
        {}
      end
      decl.lifetime_params.each do |lt|
        type_params[lt] = Types::LifetimeRef.new(lt)
      end if decl.respond_to?(:lifetime_params)
      type_param_constraints = struct_type.is_a?(Types::GenericStructDefinition) ? struct_type.type_param_constraints : {}
      fields = {}
      events = {}
      field_errors = []

      auto_lifetimes = []

      nested_scope = decl.is_a?(AST::StructDecl) ? resolve_nested_type_bindings(decl) : {}
      if decl.is_a?(AST::StructDecl) && struct_type.respond_to?(:define_nested_types)
        struct_type.define_nested_types(nested_scope)
        define_nested_type_bindings_recursive(decl, parent_name: decl.name)
      end

      decl.fields.each do |field|
        raise_sema_error("duplicate field #{decl.name}.#{field.name}") if fields.key?(field.name)
        raise_sema_error("duplicate member #{decl.name}.#{field.name}") if events.key?(field.name)
        unless raw_module?
          ensure_non_reserved_value_type_name!(
            field.name,
            kind_label: "field #{decl.name}",
            line: field.line || decl.line,
            column: field.column,
          )
        end

        begin
          field_type = resolve_type_ref(field.type, type_params:, type_param_constraints:, nested_types: nested_scope)

          # Auto-generate implicit lifetimes for bare ref[T] in struct fields
          if ref_type_without_lifetime?(field_type)
            auto_lt_name = "@_mt_#{auto_lifetimes.length}"
            auto_lifetimes << auto_lt_name
            type_params[auto_lt_name] = Types::LifetimeRef.new(auto_lt_name)
            field_type = Types::Registry.generic_instance("ref", [auto_lt_name] + field_type.arguments)
          end
          if decl.respond_to?(:lifetime_params) && (lt = ref_lifetime(field_type))
            unless decl.lifetime_params.include?(lt) || auto_lifetimes.include?(lt)
              raise_sema_error("field #{decl.name}.#{field.name} uses lifetime #{lt} not declared on struct")
            end
          end
          allow_lts = decl.respond_to?(:lifetime_params) ? (decl.lifetime_params + auto_lifetimes) : []
          validate_stored_ref_type!(field_type, "field #{decl.name}.#{field.name}", allow_lifetimes: allow_lts)
          unless proc_storage_supported_type?(field_type)
            raise_sema_error("field #{decl.name}.#{field.name} uses unsupported proc nesting")
          end
          fields[field.name] = field_type
        rescue SemanticError => e
          fields[field.name] = @error_type
          field_errors << e
          @structural_errors << e if @structural_errors
        end
      end

      unless field_errors.empty?
        struct_type.define_fields(fields)
        raise field_errors.first
      end

      if decl.is_a?(AST::StructDecl)
        decl.events.each do |event_decl|
          raise_sema_error("duplicate event #{decl.name}.#{event_decl.name}") if events.key?(event_decl.name)
          raise_sema_error("duplicate member #{decl.name}.#{event_decl.name}") if fields.key?(event_decl.name)
          unless raw_module?
            ensure_non_reserved_type_binding_name!(
              event_decl.name,
              kind_label: "event #{decl.name}",
              line: event_decl.line,
              column: event_decl.column,
            )
          end

          begin
            events[event_decl.name] = resolve_event_decl_type(
              event_decl,
              type_params:,
              type_param_constraints:,
              owner_type_name: decl.name,
              nested_types: nested_scope,
            )
          rescue SemanticError => e
            collect_structural_error(e)
          end
        end
      end

      if decl.is_a?(AST::StructDecl)
        resolve_nested_struct_fields(decl, type_params:, type_param_constraints:, external_nested_scope: nested_scope)
      end
      struct_type.define_fields(fields)
      struct_type.define_events(events) if struct_type.respond_to?(:define_events)
    end
  rescue SemanticError => e
    collect_structural_error(e)
  end
end

#resolve_and_store_offset(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 616

def resolve_and_store_offset(expression, scopes:)
  type = resolve_type_ref(expression.type)
  return unless layout_aggregate_type?(type)

  binding = lookup_value(expression.field, scopes)
  return unless binding && binding.const_value.is_a?(Types::FieldHandle)

  offset = CompileTime::Layout.offset_of(type, binding.const_value.field_name)
  return unless offset

  @const_values[@ctx.ast.node_ids[expression.object_id]] = offset
end

#resolve_attribute_binding(name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/attributes.rb', line 158

def resolve_attribute_binding(name)
  parts = name.parts

  if parts.length == 1
    binding = @ctx.attributes[parts.first]
    raise_sema_error("unknown attribute #{name}") unless binding

    return binding
  end

  if parts.length == 2 && @ctx.imports.key?(parts.first)
    imported_module = @ctx.imports.fetch(parts.first)
    raise_sema_error("#{parts.first}.#{parts.last} is private to module #{imported_module.name}") if imported_module.private_attribute?(parts.last)

    binding = imported_module.attributes[parts.last]
    raise_sema_error("unknown attribute #{name}") unless binding

    return binding
  end

  raise_sema_error("unknown attribute #{name}")
end

#resolve_attribute_name_argument(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1583

def resolve_attribute_name_argument(expression)
  case expression
  when AST::Identifier
    resolve_attribute_binding(AST::QualifiedName.new(parts: [expression.name]))
  when AST::MemberAccess
    raise_sema_error("attribute name must use a module qualifier") unless expression.receiver.is_a?(AST::Identifier)

    resolve_attribute_binding(AST::QualifiedName.new(parts: [expression.receiver.name, expression.member]))
  else
    raise_sema_error("attribute name must be an identifier or module-qualified attribute name")
  end
end

#resolve_callable(callee, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1247

def resolve_callable(callee, scopes:)
  case callee
  when AST::Identifier
    if (binding = lookup_value(callee.name, scopes))
      return [:callable_value, binding.type, nil] if callable_type?(binding.type)

      raise_sema_error("#{callee.name} is not callable")
    end

    return [:function, @ctx.top_level_functions.fetch(callee.name), nil] if @ctx.top_level_functions.key?(callee.name)
    return [:fatal, nil, nil] if callee.name == "fatal"
    return [:ref_of, nil, nil] if callee.name == "ref_of"
    return [:const_ptr_of, nil, nil] if callee.name == "const_ptr_of"
    return [:read, nil, nil] if callee.name == "read"
    return [:ptr_of, nil, nil] if callee.name == "ptr_of"
    return [:field_of, nil, nil] if callee.name == "field_of"
    return [:callable_of, nil, nil] if callee.name == "callable_of"
    return [:attribute_of, nil, nil] if callee.name == "attribute_of"
    return [:has_attribute, nil, nil] if callee.name == "has_attribute"
    return [:get, nil, nil] if callee.name == "get"

    type = @ctx.types[callee.name]
    return [:struct, type, nil] if type.is_a?(Types::Struct) || type.is_a?(Types::StringView) || task_type?(type) || type.is_a?(Types::Vector) || type.is_a?(Types::Matrix) || type.is_a?(Types::Quaternion)
    if type.is_a?(Types::GenericStructDefinition) || type.is_a?(Types::GenericVariantDefinition)
      raise_sema_error("generic type #{callee.name} requires type arguments")
    end

    raise_sema_error("unknown callable #{callee.name}")
  when AST::MemberAccess
    if callee.receiver.is_a?(AST::Identifier) && @ctx.imports.key?(callee.receiver.name)
      imported_module = @ctx.imports.fetch(callee.receiver.name)
      return [:function, imported_module.functions.fetch(callee.member), nil] if imported_module.functions.key?(callee.member)
      imported_type = imported_module.types[callee.member]
      if imported_type.is_a?(Types::GenericStructDefinition) || imported_type.is_a?(Types::GenericVariantDefinition)
        raise_sema_error("generic type #{callee.receiver.name}.#{callee.member} requires type arguments", callee)
      end

      if imported_type.is_a?(Types::Struct) || imported_type.is_a?(Types::StringView) || task_type?(imported_type) || imported_type.is_a?(Types::Vector) || imported_type.is_a?(Types::Matrix) || imported_type.is_a?(Types::Quaternion)
        return [:struct, imported_module.types.fetch(callee.member), nil]
      end

      if imported_type.is_a?(Types::Variant)
        arm_name = callee.member
        unless imported_type.arm_names.include?(arm_name)
          raise_sema_error("unknown arm #{arm_name} for variant #{imported_type}")
        end

        return [:variant_arm_ctor, [imported_type, arm_name], nil]
      end

      if imported_module.private_function?(callee.member) || imported_module.private_type?(callee.member) || imported_module.private_value?(callee.member)
        raise_sema_error("#{callee.receiver.name}.#{callee.member} is private to module #{imported_module.name}")
      end

      raise_sema_error("unknown callable #{callee.receiver.name}.#{callee.member}") unless @ctx.types.key?(callee.receiver.name)
    end

    if (type_expr = resolve_type_expression(callee.receiver))
      if type_expr.is_a?(Types::Variant)
        arm_name = callee.member
        unless type_expr.arm_names.include?(arm_name)
          raise_sema_error("unknown arm #{arm_name} for variant #{type_expr}")
        end

        return [:variant_arm_ctor, [type_expr, arm_name], nil]
      end

      if type_expr.respond_to?(:nested_types) && type_expr.nested_types.key?(callee.member)
        return [:struct, type_expr.nested_types[callee.member], nil]
      end

      method = lookup_method(type_expr, callee.member)
      method ||= lookup_static_method(type_expr, callee.member)
      return [:function, method, nil] if method && method.type.receiver_type.nil?

      raise_sema_error("unknown associated function #{type_expr}.#{callee.member}")
    end

    method_receiver_type = infer_method_receiver_type(callee.receiver, scopes:, member_name: callee.member)

    if dyn_type?(method_receiver_type)
      interface = method_receiver_type.interface_binding
      method_binding = interface.methods[callee.member]
      raise_sema_error("no method '#{callee.member}' on interface #{interface.name}") unless method_binding
      raise_sema_error("cannot call static method '#{callee.member}' on dyn value") if method_binding.kind == :static
      return [:dyn_method, method_binding, callee.receiver]
    end

    method = lookup_method(method_receiver_type, callee.member)
    return [:method, method, callee.receiver] if method

    if callee.member == "with" && struct_with_target_type?(method_receiver_type)
      return [:struct_with, method_receiver_type, callee.receiver]
    end

    if char_array_removed_text_method?(method_receiver_type, callee.member)
      raise_sema_error("#{method_receiver_type}.#{callee.member} is not available; array[char, N] is raw storage, use str_buffer[N] or an explicit helper")
    end

    if (str_buffer_method = str_buffer_method_kind(method_receiver_type, callee.member))
      return [str_buffer_method, method_receiver_type, callee.receiver]
    end

    if (event_method = event_method_kind(method_receiver_type, callee.member))
      return [event_method, method_receiver_type, callee.receiver]
    end

    if (atomic_method = atomic_method_kind(method_receiver_type, callee.member))
      return [atomic_method, method_receiver_type, callee.receiver]
    end

    if (simd_method = simd_method_kind(method_receiver_type, callee.member))
      return [simd_method, method_receiver_type, callee.receiver]
    end

    field_receiver_type = infer_field_receiver_type(callee.receiver, scopes:)
    if array_type?(field_receiver_type) && callee.member == "as_span"
      return [:array_as_span, field_receiver_type, callee.receiver]
    end

    return [:callable_value, field_receiver_type.field(callee.member), nil] if aggregate_type?(field_receiver_type) && callable_type?(field_receiver_type.field(callee.member))
    return [:callable_value, field_receiver_type.field(callee.member), nil] if aggregate_type?(field_receiver_type) && callable_type?(field_receiver_type.field(callee.member))

    if (imported_module = imported_module_with_private_method(method_receiver_type, callee.member))
      raise_sema_error("#{method_receiver_type}.#{callee.member} is private to module #{imported_module.name}")
    end

    raise_sema_error("unknown method #{method_receiver_type}.#{callee.member}")
  when AST::Specialization
    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "reinterpret"
      raise_sema_error("reinterpret requires exactly one type argument") unless callee.arguments.length == 1

      type_arg = callee.arguments.first.value
      raise_sema_error("reinterpret type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

      return [:reinterpret, resolve_type_ref(type_arg), nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "array"
      raise_sema_error("array requires exactly two type arguments") unless callee.arguments.length == 2

      array_type = resolve_type_ref(AST::TypeRef.new(name: AST::QualifiedName.new(parts: ["array"]), arguments: callee.arguments, nullable: false))
      raise_sema_error("array specialization must be array[T, N]") unless array_type?(array_type)

      return [:array, array_type, nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "simd"
      raise_sema_error("simd requires exactly two type arguments") unless callee.arguments.length == 2

      simd_type = resolve_type_ref(AST::TypeRef.new(name: AST::QualifiedName.new(parts: ["simd"]), arguments: callee.arguments, nullable: false))
      return [:simd, simd_type, nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "span"
      raise_sema_error("span requires exactly one type argument") unless callee.arguments.length == 1

      span_type = resolve_type_ref(AST::TypeRef.new(name: AST::QualifiedName.new(parts: ["span"]), arguments: callee.arguments, nullable: false))
      raise_sema_error("span specialization must be span[T]") unless span_type?(span_type)

      return [:struct, span_type, nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "zero"
      raise_sema_error("zero requires exactly one type argument") unless callee.arguments.length == 1

      type_arg = callee.arguments.first.value
      raise_sema_error("zero type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

      return [:zero, resolve_type_ref(type_arg), nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "default"
      return [:default, resolve_default_specialization(callee), nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "hash"
      return [:hash, resolve_hash_specialization(callee), nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "equal"
      return [:equal, resolve_equal_specialization(callee), nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "order"
      return [:order, resolve_order_specialization(callee), nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "attribute_arg"
      raise_sema_error("attribute_arg requires exactly one type argument") unless callee.arguments.length == 1

      type_arg = callee.arguments.first.value
      raise_sema_error("attribute_arg type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

      return [:attribute_arg, resolve_type_ref(type_arg), nil]
    end

    if callee.callee.is_a?(AST::Identifier) && callee.callee.name == "adapt"
      raise_sema_error("adapt requires exactly one type argument") unless callee.arguments.length == 1

      type_arg = callee.arguments.first.value
      raise_sema_error("adapt type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

      interface = resolve_adapt_interface(type_arg)
      return [:adapt, interface, nil]
    end

    if (callable_resolution = resolve_specialized_callable_binding(callee, scopes:))
      return callable_resolution
    end

    if (type_ref = type_ref_from_specialization(callee))
      specialized_type = resolve_type_ref(type_ref)
      return [:struct, specialized_type, nil] if specialized_type.is_a?(Types::Struct) || task_type?(specialized_type) || specialized_type.is_a?(Types::Vector) || specialized_type.is_a?(Types::Matrix) || specialized_type.is_a?(Types::Quaternion) || specialized_type.is_a?(Types::Simd)
    end

    raise_sema_error("unsupported callable specialization #{describe_expression(callee)}")
  else
    callee_type = infer_expression(callee, scopes:)
    return [:callable_value, callee_type, nil] if callable_type?(callee_type)

    raise_sema_error("unsupported callee #{describe_expression(callee)}")
  end
end

#resolve_callable_handle_argument(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1576

def resolve_callable_handle_argument(expression, scopes:)
  callable_kind, callable, _receiver = resolve_callable(expression, scopes:)
  raise_sema_error("callable_of expects a callable declaration name") unless callable_kind == :function

  Types::CallableHandle.new(describe_expression(expression), callable.ast)
end

#resolve_compile_time_type_ref(type_ref) ⇒ Object

Resolves a bare dotted reflection type expression such as field.type (where field is a compile-time field_handle bound in scope) to the concrete Types::Base it denotes. Returns nil when the type_ref is not a compile-time type expression resolvable in the current scopes. Only the plain <local>.member form is supported (no calls/indexing/type args).



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 356

def resolve_compile_time_type_ref(type_ref)
  return nil unless @type_resolution_scopes
  return nil if type_ref.arguments.any? || type_ref.nullable

  parts = type_ref.name.parts
  return nil unless parts.length >= 2

  binding = lookup_value(parts.first, @type_resolution_scopes)
  return nil unless binding && !binding.const_value.nil?

  expression = AST.build_chain_from_parts(parts)
  return nil unless expression

  value = evaluate_compile_time_const_value(expression, scopes: @type_resolution_scopes)
  value.is_a?(Types::Base) ? value : nil
end

#resolve_current_module_const_value(name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 414

def resolve_current_module_const_value(name)
  binding = @ctx.top_level_values[name]
  return unless binding&.kind == :const

  evaluate_top_level_const_value(name)
end

#resolve_default_specialization(callee) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 241

def resolve_default_specialization(callee)
  raise_sema_error("default requires exactly one type argument") unless callee.arguments.length == 1

  type_arg = callee.arguments.first.value
  raise_sema_error("default type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

  target_type = resolve_type_ref(type_arg)
  binding = resolve_explicit_default_binding(target_type, context: "default[#{target_type}]")
  raise_sema_error("default[#{target_type}] requires associated function #{target_type}.default()") unless binding

  DefaultResolution.new(
    target_type:,
    binding:,
  )
end

#resolve_enum_member_const_value(receiver_type, member_name, local_enum_type: nil, local_member_values: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 438

def resolve_enum_member_const_value(receiver_type, member_name, local_enum_type: nil, local_member_values: nil)
  return unless receiver_type.is_a?(Types::EnumBase)
  return unless receiver_type.member(member_name)

  if local_enum_type && receiver_type == local_enum_type && local_member_values&.key?(member_name)
    return local_member_values[member_name]
  end

  receiver_type.member_value(member_name)
end

#resolve_enum_members ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 564

def resolve_enum_members
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      next unless decl.is_a?(AST::EnumDecl) || decl.is_a?(AST::FlagsDecl)

      enum_type = @ctx.types.fetch(decl.name)
      backing_type = resolve_type_ref(decl.backing_type)
      unless backing_type.is_a?(Types::Primitive) && backing_type.integer?
        raise_sema_error("#{decl.name} backing type must be an integer primitive, got #{backing_type}")
      end

      member_names = []
      decl.members.each do |member|
        raise_sema_error("duplicate member #{decl.name}.#{member.name}") if member_names.include?(member.name)
        unless raw_module?
          ensure_non_reserved_value_type_name!(
            member.name,
            kind_label: "member #{decl.name}",
            line: member.line || decl.line,
            column: member.column,
          )
        end

        member_names << member.name
      end

      enum_type.define_members(backing_type, member_names)

      member_values = {}

      decl.members.each do |member|
        begin
          if member.value
            actual_type = infer_expression(member.value, scopes: [], expected_type: backing_type)
            const_value = evaluate_enum_member_const_value(member.value, enum_type:, member_values:)
          else
            const_value = (member_values.values.last&.succ || 0)
            actual_type = backing_type
          end

          compatible = types_compatible?(actual_type, backing_type, expression: member.value, scopes: [])
          compatible ||= actual_type.is_a?(Types::EnumBase) && types_compatible?(actual_type.backing_type, backing_type, expression: member.value, scopes: [])
          compatible ||= const_value.is_a?(Integer) && numeric_constant_fits_type?(const_value, backing_type)
          raise_sema_error("member #{decl.name}.#{member.name} expects #{backing_type}, got #{actual_type}", member) unless compatible

          raise_sema_error("member #{decl.name}.#{member.name} must be a compile-time integer constant", member) unless const_value.is_a?(Integer)

          member_values[member.name] = const_value
        rescue SemanticError => e
          collect_structural_error(e)
        end
      end

      enum_type.define_member_values(member_values)
    end
  rescue SemanticError => e
    collect_structural_error(e)
  end
end

#resolve_equal_specialization(callee) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 273

def resolve_equal_specialization(callee)
  raise_sema_error("equal requires exactly one type argument") unless callee.arguments.length == 1

  type_arg = callee.arguments.first.value
  raise_sema_error("equal type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

  target_type = resolve_type_ref(type_arg)
  binding = resolve_explicit_equal_binding(target_type, context: "equal[#{target_type}]")
  raise_sema_error("equal[#{target_type}] requires associated function #{target_type}.equal(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> bool") unless binding

  EqualResolution.new(
    target_type:,
    binding:,
  )
end

#resolve_event_decl_type(decl, type_params: {}, type_param_constraints: {}, owner_type_name: nil, nested_types: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 426

def resolve_event_decl_type(decl, type_params: {}, type_param_constraints: {}, owner_type_name: nil, nested_types: nil)
  raise_sema_error("event #{decl.name} capacity must be positive") unless decl.capacity.is_a?(Integer) && decl.capacity.positive?

  payload_type = decl.payload_type ? resolve_type_ref(decl.payload_type, type_params:, type_param_constraints:, nested_types:) : nil
  if payload_type
    raise_sema_error("event #{decl.name} payload cannot be ref[T] in v1") if ref_type?(payload_type)
    validate_stored_ref_type!(payload_type, "event #{decl.name} payload")
    raise_sema_error("event #{decl.name} payload uses unsupported proc nesting") unless proc_storage_supported_type?(payload_type)
    raise_sema_error("event #{decl.name} payload cannot use event storage type #{payload_type}") if noncopyable_event_storage_type?(payload_type)
  end

  Types::Event.new(
    decl.name,
    capacity: decl.capacity,
    payload_type: payload_type,
    module_name: @ctx.module_name,
    visibility: decl.visibility,
    owner_type_name: owner_type_name,
  )
end

#resolve_explicit_associated_binding(target_type, method_name, requirement_message:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 390

def resolve_explicit_associated_binding(target_type, method_name, requirement_message:)
  method = lookup_static_method(target_type, method_name)
  if method
    raise_sema_error(requirement_message) unless method.type.receiver_type.nil?

    method = instantiate_function_binding_with_receiver(method, [], receiver_type: target_type) if method.type_params.any?
    yield method

    return method
  end

  if (imported_module = imported_module_with_private_method(target_type, method_name))
    raise_sema_error("#{target_type}.#{method_name} is private to module #{imported_module.name}")
  end

  nil
end

#resolve_explicit_default_binding(target_type, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 305

def resolve_explicit_default_binding(target_type, context:)
  requirement_message = "#{context} requires associated function #{target_type}.default()"
  resolve_explicit_associated_binding(target_type, "default", requirement_message:) do |method|
    raise_sema_error("#{context} requires #{target_type}.default() to take 0 arguments") unless method.type.params.empty?
    unless types_compatible?(method.type.return_type, target_type)
      raise_sema_error("#{context} requires #{target_type}.default() to return #{target_type}, got #{method.type.return_type}")
    end
  end
end

#resolve_explicit_equal_binding(target_type, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 327

def resolve_explicit_equal_binding(target_type, context:)
  requirement_message = "#{context} requires associated function #{target_type}.equal(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> bool"
  resolve_explicit_associated_binding(target_type, "equal", requirement_message:) do |method|
    expected_param_types = [const_pointer_to(target_type), const_pointer_to(target_type)]
    unless method.type.params.map(&:type) == expected_param_types
      raise_sema_error("#{context} requires #{target_type}.equal(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> bool")
    end
    unless method.type.return_type == @ctx.types.fetch("bool")
      raise_sema_error("#{context} requires #{target_type}.equal(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> bool, got #{method.type.return_type}")
    end
  end
end

#resolve_explicit_format_append_binding(target_type, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 377

def resolve_explicit_format_append_binding(target_type, context:)
  requirement_message = "#{context} requires method #{target_type}.append_format(output: ref[std.string.String]) -> void"
  resolve_explicit_instance_binding(target_type, "append_format", requirement_message:) do |method|
    raise_sema_error("#{context} requires #{target_type}.append_format() to be non-editable") if method.type.receiver_editable
    unless method.type.params.length == 1 && string_builder_ref_type?(method.type.params.first.type)
      raise_sema_error("#{context} requires #{target_type}.append_format(output: ref[std.string.String]) -> void")
    end
    unless method.type.return_type == @ctx.types.fetch("void")
      raise_sema_error("#{context} requires #{target_type}.append_format(output: ref[std.string.String]) -> void, got #{method.type.return_type}")
    end
  end
end

#resolve_explicit_format_binding(target_type, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 353

def resolve_explicit_format_binding(target_type, context:)
  length_binding = resolve_explicit_format_len_binding(target_type, context:)
  append_binding = resolve_explicit_format_append_binding(target_type, context:)

  return [length_binding, append_binding] if length_binding && append_binding

  if length_binding || append_binding
    raise_sema_error("#{context} requires methods #{target_type}.format_len() -> ptr_uint and #{target_type}.append_format(output: ref[std.string.String]) -> void")
  end

  nil
end

#resolve_explicit_format_len_binding(target_type, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 366

def resolve_explicit_format_len_binding(target_type, context:)
  requirement_message = "#{context} requires method #{target_type}.format_len() -> ptr_uint"
  resolve_explicit_instance_binding(target_type, "format_len", requirement_message:) do |method|
    raise_sema_error("#{context} requires #{target_type}.format_len() to take 0 arguments") unless method.type.params.empty?
    raise_sema_error("#{context} requires #{target_type}.format_len() to be non-editable") if method.type.receiver_editable
    unless method.type.return_type == @ctx.types.fetch("ptr_uint")
      raise_sema_error("#{context} requires #{target_type}.format_len() -> ptr_uint, got #{method.type.return_type}")
    end
  end
end

#resolve_explicit_hash_binding(target_type, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 315

def resolve_explicit_hash_binding(target_type, context:)
  requirement_message = "#{context} requires associated function #{target_type}.hash(value: const_ptr[#{target_type}]) -> uint"
  resolve_explicit_associated_binding(target_type, "hash", requirement_message:) do |method|
    unless method.type.params.map(&:type) == [const_pointer_to(target_type)]
      raise_sema_error("#{context} requires #{target_type}.hash(value: const_ptr[#{target_type}]) -> uint")
    end
    unless method.type.return_type == @ctx.types.fetch("uint")
      raise_sema_error("#{context} requires #{target_type}.hash(value: const_ptr[#{target_type}]) -> uint, got #{method.type.return_type}")
    end
  end
end

#resolve_explicit_instance_binding(target_type, method_name, requirement_message:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 408

def resolve_explicit_instance_binding(target_type, method_name, requirement_message:)
  method = lookup_method(target_type, method_name)
  if method
    raise_sema_error(requirement_message) if method.type.receiver_type.nil?

    method = instantiate_function_binding_with_receiver(method, [], receiver_type: target_type) if method.type_params.any?
    yield method

    return method
  end

  if (imported_module = imported_module_with_private_method(target_type, method_name))
    raise_sema_error("#{target_type}.#{method_name} is private to module #{imported_module.name}")
  end

  nil
end

#resolve_explicit_order_binding(target_type, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 340

def resolve_explicit_order_binding(target_type, context:)
  requirement_message = "#{context} requires associated function #{target_type}.order(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> int"
  resolve_explicit_associated_binding(target_type, "order", requirement_message:) do |method|
    expected_param_types = [const_pointer_to(target_type), const_pointer_to(target_type)]
    unless method.type.params.map(&:type) == expected_param_types
      raise_sema_error("#{context} requires #{target_type}.order(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> int")
    end
    unless method.type.return_type == @ctx.types.fetch("int")
      raise_sema_error("#{context} requires #{target_type}.order(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> int, got #{method.type.return_type}")
    end
  end
end

#resolve_foreign_call_expression(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1151

def resolve_foreign_call_expression(expression, scopes:)
  call = expression
  return unless call.is_a?(AST::Call)

  callable_kind, callable, _receiver = resolve_callable(call.callee, scopes:)
  return unless callable_kind == :function

  callable = specialize_function_binding(
    callable,
    call.arguments,
    scopes:,
    receiver_type: callable_receiver_type_for_specialization(call.callee, scopes:),
  ) if callable.type_params.any?
  return unless foreign_function_binding?(callable)

  { call:, binding: callable }
rescue SemanticError
  nil
end

#resolve_generic_type_param_constraints ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 288

def resolve_generic_type_param_constraints
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      next unless decl.is_a?(AST::StructDecl) || decl.is_a?(AST::VariantDecl) || decl.is_a?(AST::InterfaceDecl)
      next if decl.type_params.empty?

      constraints = resolve_type_param_constraints(decl.type_params)
      if decl.is_a?(AST::InterfaceDecl)
        @ctx.interfaces[decl.name] = @ctx.interfaces.fetch(decl.name).with(type_param_constraints: constraints)
      else
        @ctx.types.fetch(decl.name).define_type_param_constraints(constraints)
      end
    end
  end
end

#resolve_hash_specialization(callee) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 257

def resolve_hash_specialization(callee)
  raise_sema_error("hash requires exactly one type argument") unless callee.arguments.length == 1

  type_arg = callee.arguments.first.value
  raise_sema_error("hash type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

  target_type = resolve_type_ref(type_arg)
  binding = resolve_explicit_hash_binding(target_type, context: "hash[#{target_type}]")
  raise_sema_error("hash[#{target_type}] requires associated function #{target_type}.hash(value: const_ptr[#{target_type}]) -> uint") unless binding

  HashResolution.new(
    target_type:,
    binding:,
  )
end

#resolve_imported_module_const_value(import_name, value_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 425

def resolve_imported_module_const_value(import_name, value_name)
  imported_module = @ctx.imports[import_name]
  return unless imported_module
  if imported_module.private_value?(value_name)
    raise_sema_error("#{import_name}.#{value_name} is private to module #{imported_module.name}")
  end

  binding = imported_module.values[value_name]
  return unless binding&.kind == :const

  binding.const_value
end

#resolve_interface_method_binding(method_decl, type_params: {}, type_param_constraints: {}) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 379

def resolve_interface_method_binding(method_decl, type_params: {}, type_param_constraints: {})
  raise_sema_error("interface method #{method_decl.name} cannot be async") if method_decl.async

  params = []
  seen = {}
  method_decl.params.each do |param|
    raise_sema_error("duplicate parameter #{param.name} in #{method_decl.name}") if seen.key?(param.name)

    seen[param.name] = true
    type = resolve_type_ref(param.type, type_params:, type_param_constraints:)
    validate_parameter_ref_type!(type, function_name: method_decl.name, parameter_name: param.name, external: false)
    validate_parameter_proc_type!(type, function_name: method_decl.name, parameter_name: param.name, external: false, foreign: false)
    params << Types::Registry.parameter(param.name, type)
  end

  return_type = method_decl.return_type ? resolve_type_ref(method_decl.return_type, type_params:, type_param_constraints:) : @ctx.types.fetch("void")
  validate_return_ref_type!(return_type, function_name: method_decl.name)
  validate_return_proc_type!(return_type, function_name: method_decl.name)

  InterfaceMethodBinding.new(
    name: method_decl.name,
    params: params.freeze,
    return_type: return_type,
    kind: method_decl.kind,
    async: method_decl.async,
    ast: method_decl,
  )
end

#resolve_interface_ref(interface_ref) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 130

def resolve_interface_ref(interface_ref)
  parts = interface_ref.parts

  interface = if parts.length == 1
                @ctx.interfaces[parts.first]
              elsif parts.length == 2 && @ctx.imports.key?(parts.first)
                imported_module = @ctx.imports.fetch(parts.first)
                raw = imported_module.interfaces[parts.last]
                if imported_module.private_interface?(parts.last)
                  raise_sema_error("#{parts.first}.#{parts.last} is private to module #{imported_module.name}")
                end
                raw
              end

  raise_sema_error("unknown interface #{interface_ref}", interface_ref) unless interface

  if interface_ref.type_arguments.any?
    raise_sema_error("interface #{interface.name} is not generic") unless interface.is_a?(GenericInterfaceBinding)

    arguments = interface_ref.type_arguments.map { |arg| resolve_type_ref(arg) }
    interface.instantiate(arguments)
  else
    raise_sema_error("generic interface #{interface.name} requires type arguments") if interface.is_a?(GenericInterfaceBinding)

    interface
  end
end

#resolve_methods_receiver_target(type_ref) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1025

def resolve_methods_receiver_target(type_ref)
  if type_ref.is_a?(AST::TypeRef)
    generic_type = resolve_named_generic_type(type_ref.name.parts)
    if generic_type.is_a?(Types::GenericStructDefinition) || generic_type.is_a?(Types::GenericVariantDefinition)
      receiver_type_param_names = validate_methods_receiver_type_arguments!(type_ref, generic_type)
      receiver_type_params = receiver_type_param_names.to_h { |name| [name, Types::TypeVar.new(name)] }
      receiver_type_param_constraints = generic_type.respond_to?(:type_param_constraints) ? generic_type.type_param_constraints : {}
      receiver_type = resolve_type_ref(type_ref, type_params: receiver_type_params, type_param_constraints: receiver_type_param_constraints)
      return [generic_type, receiver_type, receiver_type_param_names, receiver_type_param_constraints]
    end

    begin
      receiver_type = resolve_type_ref(type_ref)
      unless receiver_type.is_a?(Types::Struct) || receiver_type.is_a?(Types::StructInstance) || receiver_type.is_a?(Types::Opaque) || receiver_type.is_a?(Types::GenericInstance) || receiver_type.is_a?(Types::Nullable) || receiver_type.is_a?(Types::StringView) || receiver_type.is_a?(Types::Primitive) || receiver_type.is_a?(Types::Variant) || receiver_type.is_a?(Types::VariantInstance) || vector_type?(receiver_type) || matrix_type?(receiver_type) || quaternion_type?(receiver_type)
        raise_sema_error("extending target #{type_ref} must be a struct, opaque, nullable/generic receiver, variant, or str")
      end

      return [receiver_type, receiver_type, [], {}]
    rescue MilkTea::SemanticError => error
      receiver_type_param_names = methods_receiver_type_argument_names!(type_ref)
      raise error if receiver_type_param_names.empty?

      receiver_type_params = receiver_type_param_names.to_h { |name| [name, Types::TypeVar.new(name)] }
      receiver_type = resolve_type_ref(type_ref, type_params: receiver_type_params)
      return [method_dispatch_receiver_type(receiver_type), receiver_type, receiver_type_param_names, {}]
    end
  end

  receiver_type = resolve_type_ref(type_ref)
  unless receiver_type.is_a?(Types::Struct) || receiver_type.is_a?(Types::StructInstance) || receiver_type.is_a?(Types::Opaque) || receiver_type.is_a?(Types::GenericInstance) || receiver_type.is_a?(Types::Nullable) || receiver_type.is_a?(Types::StringView) || receiver_type.is_a?(Types::Primitive) || receiver_type.is_a?(Types::Variant) || receiver_type.is_a?(Types::VariantInstance) || vector_type?(receiver_type) || matrix_type?(receiver_type) || quaternion_type?(receiver_type)
    raise_sema_error("extending target #{type_ref} must be a struct, opaque, nullable/generic receiver, variant, or str")
  end

  [receiver_type, receiver_type, [], {}]
end

#resolve_name_in_precheck_scopes(name, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 409

def resolve_name_in_precheck_scopes(name, scopes)
  scopes.reverse_each do |scope|
    return scope[name] if scope.key?(name)
  end

  nil
end

#resolve_named_generic_type(parts) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 813

def resolve_named_generic_type(parts)
  if parts.length == 1
    type = @ctx.types[parts.first]
    return type if type.is_a?(Types::GenericStructDefinition) || type.is_a?(Types::GenericVariantDefinition)
  elsif parts.length >= 2
    type = resolve_nested_type_ref(parts)
    return type if type.is_a?(Types::GenericStructDefinition) || type.is_a?(Types::GenericVariantDefinition)
    if @ctx.imports.key?(parts.first)
      type = @ctx.imports.fetch(parts.first).types[parts.last]
      return type if type.is_a?(Types::GenericStructDefinition) || type.is_a?(Types::GenericVariantDefinition)
    end
  end

  nil
end

#resolve_named_literal_type_argument(type_ref) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 401

def resolve_named_literal_type_argument(type_ref)
  value = case type_ref.name.parts.length
          when 1
            resolve_current_module_const_value(type_ref.name.parts.first)
          when 2
            resolve_imported_module_const_value(type_ref.name.parts.first, type_ref.name.parts.last)
          end

  return unless value.is_a?(Integer) || value.is_a?(Float)

  Types::LiteralTypeArg.new(value)
end

#resolve_nested_struct_fields(parent_decl, parent_name: parent_decl.name, type_params:, type_param_constraints:, external_nested_scope: {}) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 803

def resolve_nested_struct_fields(parent_decl, parent_name: parent_decl.name, type_params:, type_param_constraints:, external_nested_scope: {})
  parent_decl.nested_types.each do |nested|
    next unless nested.type_params.empty?
    qualified_name = "#{parent_name}.#{nested.name}"
    nested_type = @ctx.types[qualified_name]
    next unless nested_type.is_a?(Types::Struct)
    nested_type.ast_declaration = nested
    nested_scope = nested_type.nested_types.merge(external_nested_scope)
    fields = {}
    nested.fields.each do |field|
      raise_sema_error("duplicate field #{qualified_name}.#{field.name}") if fields.key?(field.name)
      begin
        field_type = resolve_type_ref(field.type, type_params:, type_param_constraints:, nested_types: nested_scope)
        validate_stored_ref_type!(field_type, "field #{qualified_name}.#{field.name}")
        fields[field.name] = field_type
      rescue SemanticError => e
        fields[field.name] = @error_type
        @structural_errors << e if @structural_errors
      end
    end
    nested_type.define_fields(fields)
    nested_events = {}
    nested.events.each do |event_decl|
      raise_sema_error("duplicate event #{qualified_name}.#{event_decl.name}") if nested_events.key?(event_decl.name)
      begin
        nested_events[event_decl.name] = resolve_event_decl_type(event_decl, type_params:, type_param_constraints:, owner_type_name: qualified_name, nested_types: nested_scope)
      rescue SemanticError => e
        collect_structural_error(e)
      end
    end
    nested_type.define_events(nested_events)
    resolve_nested_struct_fields(nested, parent_name: qualified_name, type_params:, type_param_constraints:, external_nested_scope: nested_scope)
  end
end

#resolve_nested_type_bindings(parent_decl, parent_name: parent_decl.name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 838

def resolve_nested_type_bindings(parent_decl, parent_name: parent_decl.name)
  bindings = {}
  parent_decl.nested_types.each do |nested|
    qualified_name = "#{parent_name}.#{nested.name}"
    nested_type = @ctx.types[qualified_name]
    bindings[nested.name] = nested_type if nested_type
  end
  bindings
end

#resolve_nested_type_ref(parts) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 802

def resolve_nested_type_ref(parts)
  current = @ctx.types[parts.first]
  return nil unless current.is_a?(Types::Struct) || current.is_a?(Types::GenericStructDefinition)
  parts[1..].each do |part|
    nested = current.respond_to?(:nested_types) ? current.nested_types[part] : nil
    return nil unless nested
    current = nested
  end
  current
end

#resolve_non_nullable_type(type_ref, type_params: {}, type_param_constraints: {}, nested_types: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 212

def resolve_non_nullable_type(type_ref, type_params: {}, type_param_constraints: {}, nested_types: nil)
  if type_ref.is_a?(AST::FunctionType)
    params = type_ref.params.map do |param|
      Types::Registry.parameter(param.name, resolve_type_ref(param.type, type_params:, type_param_constraints:))
    end
    return Types::Registry.function(nil, params:, return_type: resolve_type_ref(type_ref.return_type, type_params:, type_param_constraints:))
  end

  if type_ref.is_a?(AST::ProcType)
    params = type_ref.params.map do |param|
      Types::Registry.parameter(param.name, resolve_type_ref(param.type, type_params:, type_param_constraints:))
    end
    return Types::Registry.proc(params:, return_type: resolve_type_ref(type_ref.return_type, type_params:, type_param_constraints:))
  end

  if type_ref.is_a?(AST::DynType)
    interface = resolve_interface_ref(type_ref.interface)
    raise_sema_error("generic interface #{interface.name} requires type arguments") if interface.is_a?(GenericInterfaceBinding)
    type_arguments = interface.type_arguments || []
    type = Types::Dyn.new(interface, type_arguments)
    type = Types::Registry.nullable(type) if type_ref.nullable
    return type
  end

  if type_ref.is_a?(AST::TupleType)
    names = []
    element_types = []
    type_ref.element_types.each do |et|
      if et.is_a?(AST::Argument)
        names << et.name
        element_types << resolve_type_ref(et.value, type_params:, type_param_constraints:)
      else
        names << nil
        element_types << resolve_type_ref(et, type_params:, type_param_constraints:)
      end
    end
    has_named = names.any?
    return Types::Registry.tuple(element_types, field_names: has_named ? names : nil)
  end

  parts = type_ref.name.parts

  if type_ref.arguments.any?
    name = parts.join(".")
    arguments = type_ref.arguments.map { |argument| resolve_type_argument(argument.value, type_params:, type_param_constraints:) }

    if name != "ref" && arguments.any? { |argument| contains_ref_type?(argument) && !stored_ref_supported_type?(argument) }
      raise_sema_error("ref types cannot be nested inside #{name}", type_ref)
    end

    if name == "Task"
      validate_generic_type!(name, arguments)
      return Types::Registry.task(arguments[0])
    end

    if (generic_type = resolve_named_generic_type(parts))
      begin
        validate_generic_type_param_constraints!(generic_type, arguments, context: "type #{generic_type}", available_type_param_constraints: type_param_constraints)
        return generic_type.instantiate(arguments)
      rescue ArgumentError => error
        raise_sema_error(error.message)
      end
    end

    # Handle types with lifetime params only (no type params)
    if arguments.all? { |a| a.is_a?(Types::LifetimeRef) }
      type = @ctx.types[name]
      if type.is_a?(Types::Struct) && type.lifetime_params&.any?
        lifetime_args = arguments.select { |a| a.is_a?(Types::LifetimeRef) }.map(&:name)
        if lifetime_args.to_set == type.lifetime_params.to_set
          return type
        end
      end
    end

    validate_generic_type!(name, arguments)
    return Types::Registry.span(arguments.first) if name == "span"

    return Types::Registry.soa(arguments[0], count: arguments[1].value) if name == "SoA"

    return Types::Registry.simd(arguments[0], lane_count: arguments[1].value) if name == "simd"

    arguments = [type_ref.lifetime] + arguments if name == "ref" && type_ref.lifetime
    return Types::Registry.generic_instance(name, arguments)
  end

  if parts.length == 1 && type_ref.lifetime
    raise_sema_error("lifetime annotations are only valid on ref types, got #{type_ref.name}", type_ref)
  end

  if parts.length == 1
    return type_params.fetch(parts.first) if type_params.key?(parts.first)

    if nested_types && (type = nested_types[parts.first])
      return type
    end

    if parts.first.start_with?("@")
      raise_sema_error("unknown lifetime #{parts.first}", type_ref)
    end

    type = @ctx.types[parts.first]
    unless type
      type_names = @ctx.types.keys
      suggestion = suggest_name(parts.first, type_names)
      unless suggestion
        suggestion = import_suggestion_for_type(parts.first)
      end
      raise_sema_error("unknown type #{parts.first}", type_ref, suggestion: suggestion ? "did you mean '#{suggestion}'?" : nil)
    end
    raise_sema_error("generic type #{parts.first} requires type arguments", type_ref) if type.is_a?(Types::GenericStructDefinition) || type.is_a?(Types::GenericVariantDefinition)

    return type
  end

  if parts.length >= 2
    type = resolve_nested_type_ref(parts)
    return type if type
  end

  if parts.length == 2 && @ctx.imports.key?(parts.first)
    imported_module = @ctx.imports.fetch(parts.first)
    type = imported_module.types[parts.last]
    if imported_module.private_type?(parts.last)
      raise_sema_error("#{parts.first}.#{parts.last} is private to module #{imported_module.name}", type_ref)
    end
    raise_sema_error("unknown type #{type_ref.name}", type_ref) unless type
    raise_sema_error("generic type #{type_ref.name} requires type arguments", type_ref) if type.is_a?(Types::GenericStructDefinition) || type.is_a?(Types::GenericVariantDefinition)

    return type
  end

  if @compile_time_depth&.positive? && (ct_type = resolve_compile_time_type_ref(type_ref))
    return ct_type
  end

  raise_sema_error("unknown type #{type_ref.name}", type_ref, suggestion: import_suggestion_for_type(type_ref.name))
end

#resolve_order_specialization(callee) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 289

def resolve_order_specialization(callee)
  raise_sema_error("order requires exactly one type argument") unless callee.arguments.length == 1

  type_arg = callee.arguments.first.value
  raise_sema_error("order type argument must be a type") unless type_arg.is_a?(AST::TypeRef)

  target_type = resolve_type_ref(type_arg)
  binding = resolve_explicit_order_binding(target_type, context: "order[#{target_type}]")
  raise_sema_error("order[#{target_type}] requires associated function #{target_type}.order(left: const_ptr[#{target_type}], right: const_ptr[#{target_type}]) -> int") unless binding

  OrderResolution.new(
    target_type:,
    binding:,
  )
end

#resolve_qualified_type_name(parts) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 347

def resolve_qualified_type_name(parts)
  return nil unless parts.length >= 2

  if @ctx.imports.key?(parts.first)
    imported_module = @ctx.imports.fetch(parts.first)
    type = imported_module.types[parts.last]
    if imported_module.private_type?(parts.last)
      raise_sema_error("#{parts.first}.#{parts.last} is private to module #{imported_module.name}")
    end
    raise_sema_error("unknown type #{parts.join('.')} for struct destructure") unless type
    return type
  end

  parent_type = @ctx.types[parts.first]
  if parent_type.respond_to?(:nested_types) && parent_type.nested_types.key?(parts.last)
    return parent_type.nested_types[parts.last]
  end

  raise_sema_error("unknown type #{parts.join('.')} for struct destructure")
end

#resolve_receiver_name_for_call_inference(callee, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 577

def resolve_receiver_name_for_call_inference(callee, scopes)
  case callee.receiver
  when AST::Identifier
    if callee.receiver.name == "this"
      binding = lookup_value("this", scopes)
      return nil unless binding
      this_type = receiver_type_for_fields(binding.type)
      this_type&.name
    else
      callee.receiver.name
    end
  end
end

#resolve_reflection_target_argument(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1564

def resolve_reflection_target_argument(expression, scopes:)
  if (type_expr = resolve_type_expression(expression))
    handle = struct_handle_for_type(type_expr)
    return handle if handle
  end

  handle = evaluate_compile_time_const_value(expression, scopes:)
  return handle if handle.is_a?(Types::FieldHandle) || handle.is_a?(Types::CallableHandle)

  raise_sema_error("attribute reflection expects a struct type, field handle, or callable handle")
end

#resolve_specialization_type_arguments(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 163

def resolve_specialization_type_arguments(expression)
  expression.arguments.map do |argument|
    resolve_type_argument(argument.value, type_params: current_type_params)
  end
end

#resolve_specialized_callable_binding(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 113

def resolve_specialized_callable_binding(expression, scopes:)
  callable_kind = :function
  receiver = nil
  receiver_type = nil
  binding = case expression.callee
  when AST::Identifier
    @ctx.top_level_functions[expression.callee.name]
  when AST::MemberAccess
    if expression.callee.receiver.is_a?(AST::Identifier) && @ctx.imports.key?(expression.callee.receiver.name)
      imported_module = @ctx.imports.fetch(expression.callee.receiver.name)
      imported_function = imported_module.functions[expression.callee.member]
      if imported_function.nil? && imported_module.private_function?(expression.callee.member)
        raise_sema_error("#{expression.callee.receiver.name}.#{expression.callee.member} is private to module #{imported_module.name}")
      end

      imported_function
    elsif (type_expr = resolve_type_expression(expression.callee.receiver))
      associated_function = lookup_method(type_expr, expression.callee.member)
      if associated_function&.type&.receiver_type.nil?
        receiver_type = type_expr
        associated_function
      else
        if (imported_module = imported_module_with_private_method(type_expr, expression.callee.member))
          raise_sema_error("#{type_expr}.#{expression.callee.member} is private to module #{imported_module.name}")
        end

        nil
      end
    else
      receiver_type = infer_method_receiver_type(expression.callee.receiver, scopes:, member_name: expression.callee.member)
      method = lookup_method(receiver_type, expression.callee.member)
      if method
        callable_kind = :method
        receiver = expression.callee.receiver
        method
      else
        if (imported_module = imported_module_with_private_method(receiver_type, expression.callee.member))
          raise_sema_error("#{receiver_type}.#{expression.callee.member} is private to module #{imported_module.name}")
        end

        nil
      end
    end
  end
  return nil unless binding

  type_arguments = resolve_specialization_type_arguments(expression)
  [callable_kind, instantiate_function_binding_with_receiver(binding, type_arguments, receiver_type:), receiver]
end

#resolve_struct_handle_argument(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1555

def resolve_struct_handle_argument(expression, scopes:)
  if (type_expr = resolve_type_expression(expression))
    handle = struct_handle_for_type(type_expr)
    return handle if handle
  end

  raise_sema_error("field_of expects a struct type expression")
end

#resolve_type_aliases ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 304

def resolve_type_aliases
  @ctx.ast.declarations.grep(AST::TypeAliasDecl).each do |decl|
    ensure_available_type_name!(decl.name)
    @ctx.types[decl.name] = resolve_type_ref(decl.target)
  rescue SemanticError => e
    collect_structural_error(e)
  end
end

#resolve_type_argument(argument, type_params: current_type_params, type_param_constraints: current_type_param_constraints) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 373

def resolve_type_argument(argument, type_params: current_type_params, type_param_constraints: current_type_param_constraints)
  case argument
  when AST::TypeRef
    resolve_type_argument_ref(argument, type_params:, type_param_constraints:)
  when AST::FunctionType, AST::ProcType
    resolve_type_ref(argument, type_params:, type_param_constraints:)
  when AST::IntegerLiteral, AST::FloatLiteral
    Types::LiteralTypeArg.new(argument.value)
  else
    raise_sema_error("unsupported type argument #{argument.class.name}")
  end
end

#resolve_type_argument_ref(type_ref, type_params:, type_param_constraints:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 386

def resolve_type_argument_ref(type_ref, type_params:, type_param_constraints:)
  return resolve_type_ref(type_ref, type_params:, type_param_constraints:) unless literal_type_argument_name_candidate?(type_ref)

  resolve_type_ref(type_ref, type_params:, type_param_constraints:)
rescue SemanticError => error
  literal_type_argument = resolve_named_literal_type_argument(type_ref)
  return literal_type_argument if literal_type_argument

  raise error
end

#resolve_type_expression(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 975

def resolve_type_expression(expression)
  case expression
  when AST::Identifier
    return current_type_params[expression.name] if current_type_params.key?(expression.name)

    @ctx.types[expression.name]
  when AST::MemberAccess
    return nil unless expression.receiver.is_a?(AST::Identifier)

    if @ctx.imports.key?(expression.receiver.name)
      imported_module = @ctx.imports.fetch(expression.receiver.name)
      if imported_module.private_type?(expression.member)
        raise_sema_error("#{expression.receiver.name}.#{expression.member} is private to module #{imported_module.name}")
      end

      return imported_module.types[expression.member]
    end

    parent_type = @ctx.types[expression.receiver.name]
    return parent_type.nested_types[expression.member] if parent_type.respond_to?(:nested_types) && parent_type.nested_types.key?(expression.member)

    nil
  when AST::Specialization
    type_ref = type_ref_from_specialization(expression)
    return nil unless type_ref

    resolve_type_ref(type_ref)
  end
end

#resolve_type_member(type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 98

def resolve_type_member(type, name)
  case type
  when Types::Enum, Types::Flags
    type.member(name)
  when Types::Variant
    return type if type.arm_names.include?(name) && !type.has_payload?(name)

    nil
  end
end

#resolve_type_param_constraints(type_params) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 208

def resolve_type_param_constraints(type_params)
  type_params.each_with_object({}) do |type_param, constraints|
    if type_param.is_a?(AST::ValueTypeParam)
      ensure_non_reserved_value_type_name!(
        type_param.name,
        kind_label: "type parameter",
        line: type_param.line,
        column: type_param.column,
        length: type_param.length,
      )
      next
    end

    ensure_non_reserved_value_type_name!(
      type_param.name,
      kind_label: "type parameter",
      line: type_param.line,
      column: type_param.column,
      length: type_param.length,
    )
    next if type_param.constraints.empty?

    resolved_interfaces = []
    seen_interfaces = {}

    type_param.constraints.each do |constraint|
      case constraint.kind
      when :interface
        interface = resolve_interface_ref(constraint.interface_ref)
        raise_sema_error("duplicate interface constraint #{type_param.name} implements #{interface.name}") if seen_interfaces.key?(interface)

        seen_interfaces[interface] = true
        resolved_interfaces << interface
      else
        raise_sema_error("unsupported type parameter constraint #{constraint.kind}")
      end
    end

    constraints[type_param.name] = TypeParamConstraintBinding.new(
      interfaces: resolved_interfaces.freeze,
    )
  end
end

#resolve_type_ref(type_ref, type_params: current_type_params, type_param_constraints: current_type_param_constraints, nested_types: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 203

def resolve_type_ref(type_ref, type_params: current_type_params, type_param_constraints: current_type_param_constraints, nested_types: nil)
  base = resolve_non_nullable_type(type_ref, type_params:, type_param_constraints:, nested_types:)
  return base if type_ref.is_a?(AST::FunctionType) || type_ref.is_a?(AST::ProcType) || type_ref.is_a?(AST::TupleType)

  raise_sema_error("ref types are non-null and cannot be nullable", type_ref) if type_ref.nullable && ref_type?(base)

  type_ref.nullable ? Types::Registry.nullable(base) : base
end

#resolve_variant_arms ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 624

def resolve_variant_arms
  expanded_declarations.each do |decl|
    with_error_node(decl) do
      next unless decl.is_a?(AST::VariantDecl)

      variant_type = @ctx.types.fetch(decl.name)
      type_params = if variant_type.is_a?(Types::GenericVariantDefinition)
        seen = {}
        variant_type.type_params.each_with_object({}) do |name, params|
          raise_sema_error("duplicate type parameter #{decl.name}[#{name}]") if seen.key?(name)

          seen[name] = true
          params[name] = Types::TypeVar.new(name)
        end
      else
        {}
      end
      type_param_constraints = variant_type.is_a?(Types::GenericVariantDefinition) ? variant_type.type_param_constraints : {}
      seen_arms = []
      arms_hash = {}
      decl.arms.each do |arm|
        begin
          raise_sema_error("duplicate arm #{decl.name}.#{arm.name}") if seen_arms.include?(arm.name)
          unless raw_module?
            ensure_non_reserved_value_type_name!(
              arm.name,
              kind_label: "arm #{decl.name}",
              line: arm.line || decl.line,
              column: arm.column,
            )
          end

          seen_arms << arm.name
          field_types = {}
          seen_fields = []
          arm_field_errors = []
          arm.fields.each do |field|
            begin
              raise_sema_error("duplicate field #{arm.name}.#{field.name}") if seen_fields.include?(field.name)
              unless raw_module?
                ensure_non_reserved_value_type_name!(
                  field.name,
                  kind_label: "field #{decl.name}.#{arm.name}",
                  line: field.line || decl.line,
                  column: field.column,
                )
              end

              seen_fields << field.name
              field_type = resolve_type_ref(field.type, type_params:, type_param_constraints:)
              validate_stored_ref_type!(field_type, "field #{decl.name}.#{arm.name}.#{field.name}")
              unless proc_storage_supported_type?(field_type)
                raise_sema_error("field #{decl.name}.#{arm.name}.#{field.name} uses unsupported proc nesting")
              end
              field_types[field.name] = field_type
            rescue SemanticError => e
              field_types[field.name] = @error_type
              arm_field_errors << e
              @structural_errors << e if @structural_errors
            end
          end

          raise arm_field_errors.first unless arm_field_errors.empty?
          arms_hash[arm.name] = field_types
        rescue SemanticError => e
          collect_structural_error(e)
        end
      end

      variant_type.define_arms(arms_hash)
    end
  rescue SemanticError => e
    collect_structural_error(e)
  end
end

#resolved_attribute_applications_for_target(target) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 6

def resolved_attribute_applications_for_target(target)
  target_id = case target
  when Types::StructHandle then target.declaration.object_id
  when Types::FieldHandle then target.field_declaration.object_id
  when Types::CallableHandle then target.declaration.object_id
  end
  return [] unless target_id

  applications = @ctx.resolved_attribute_applications[target_id]
  return applications if applications

  @ctx.imports.each_value do |imported_module|
    applications = imported_module.attribute_applications[target_id]
    return applications if applications
  end

  []
end

#result_let_else_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 810

def result_let_else_type?(type)
  return false unless type.is_a?(Types::Variant)

  success_fields = type.arm("success")
  failure_fields = type.arm("failure")
  success_fields && success_fields.length == 1 && success_fields.key?("value") &&
    failure_fields && failure_fields.length == 1 && failure_fields.key?("error")
end

#run_nullability_pre_pass(binding, scopes) ⇒ Object

Runs a strict binding-ID nullability pass before statement checks. Resolution is computed with a lexical pre-check walk so shadowed names are disambiguated without relying on name fallback.



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 56

def run_nullability_pre_pass(binding, scopes)
  return unless binding.ast.respond_to?(:body)

  @nullability_flow_result = nil
  resolution = precheck_binding_resolution(binding.ast.body, scopes)
  graph = ControlFlow::Builder.new(
    binding_resolution: ControlFlow::BindingResolution.new(
      identifier_binding_ids: resolution.identifier_binding_ids,
      declaration_binding_ids: resolution.declaration_binding_ids,
      mutating_argument_identifier_ids: resolution.mutating_argument_identifier_ids,
    ),
    strict_binding_ids: true,
  ).build(binding.ast.body)
  @nullability_flow_result = ControlFlow::NullabilityFlow.solve(graph)
end

#safe_reference_source_expression?(expression, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1247

def safe_reference_source_expression?(expression, scopes:)
  case expression
  when AST::Identifier
    true
  when AST::MemberAccess, AST::IndexAccess
    safe_reference_source_expression?(expression.receiver, scopes:)
  when AST::BinaryOp
    unsafe_context?
  when AST::Call
    return false unless expression.arguments.length == 1 && expression.arguments.first.name.nil?

    if read_call?(expression)
      argument_type = infer_expression(expression.arguments.first.value, scopes:)
      ref_type?(argument_type) || pointer_type?(argument_type)
    else
      false
    end
  else
    false
  end
end

#same_attribute_binding?(left, right) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 31

def same_attribute_binding?(left, right)
  left.name == right.name && left.module_name == right.module_name
end

#scopes_with_refinements(scopes, refinements) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 20

def scopes_with_refinements(scopes, refinements)
  return scopes if refinements.nil? || refinements.empty?

  base_scopes = scopes.last.is_a?(FlowScope) ? scopes[0...-1] : scopes
  merged_refinements = if scopes.last.is_a?(FlowScope)
    scopes.last.each_with_object({}) do |(name, binding), result|
      result[name] = if name.is_a?(String) && binding.respond_to?(:type)
        binding.type
      else
        binding
      end
    end
  else
    {}
  end
  merged_refinements = merge_refinements(merged_refinements, refinements)
  flow_scope = FlowScope.new

  merged_refinements.each do |name, refined_type|
    unless name.is_a?(String)
      flow_scope[name] = refined_type
      next
    end

    binding = lookup_value(name, base_scopes)
    next unless binding

    flow_scope[name] = binding.with_flow_type(refined_type)
  end

  return base_scopes if flow_scope.empty?

  base_scopes + [flow_scope]
end

#set_const_value(name, value) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 239

def set_const_value(name, value)
  binding = @ctx.top_level_values.fetch(name)
  @ctx.top_level_values[name] = ValueBinding.new(
    id: binding.id,
    name: binding.name,
    storage_type: binding.storage_type,
    flow_type: binding.flow_type,
    mutable: binding.mutable,
    kind: binding.kind,
    const_value: value,
  )
  @evaluated_const_values[name] = true
end

#simd_bitwise_result(left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 240

def simd_bitwise_result(left_type, right_type)
  return nil unless simd_type?(left_type) && simd_type?(right_type) && left_type == right_type

  left_type
end

#simd_method_kind(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 660

def simd_method_kind(receiver_type, name)
  return unless simd_type?(receiver_type)

  SIMD_METHOD_KINDS[name]
end

#simd_mod_result(left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 246

def simd_mod_result(left_type, right_type)
  return nil unless simd_type?(left_type) && left_type.element_type.integer?
  return nil unless right_type == left_type.element_type || (simd_type?(right_type) && right_type == left_type)

  left_type
end

#simd_op_result(operator, left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 224

def simd_op_result(operator, left_type, right_type)
  if simd_type?(left_type) && simd_type?(right_type) && left_type.element_type == right_type.element_type && left_type.lane_count == right_type.lane_count
    return left_type if operator == "+" || operator == "-" || operator == "*" || operator == "/"
  end

  if simd_type?(left_type) && right_type.numeric? && right_type == left_type.element_type
    return left_type if operator == "*" || operator == "/"
  end

  if left_type.numeric? && simd_type?(right_type) && left_type == right_type.element_type
    return right_type if operator == "*"
  end

  nil
end

#simd_shift_result(left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 253

def simd_shift_result(left_type, right_type)
  return nil unless simd_type?(left_type) && left_type.element_type.integer?
  return nil unless right_type.is_a?(Types::Primitive) && right_type.integer?

  left_type
end

#simd_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 721

def simd_type?(type)
  type.is_a?(Types::Simd)
end

#simple_foreign_argument_expression?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1205

def simple_foreign_argument_expression?(expression)
  case expression
  when AST::Identifier, AST::IntegerLiteral, AST::FloatLiteral, AST::StringLiteral, AST::BooleanLiteral, AST::NullLiteral
    true
  when AST::MemberAccess
    simple_foreign_argument_expression?(expression.receiver)
  else
    false
  end
end

#sized_layout_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 648

def sized_layout_type?(type)
  case type
  when Types::Primitive, Types::Struct, Types::StructInstance, Types::Union, Types::Enum, Types::Flags, Types::Variant, Types::Span, Types::StringView, Types::Task, Types::Event, Types::Subscription
    true
  when Types::Nullable
    true
  when Types::GenericInstance
    pointer_type?(type) || array_type?(type) || str_buffer_type?(type)
  else
    false
  end
end

#snapshot_attribute_applications ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 124

def snapshot_attribute_applications
  @ctx.resolved_attribute_applications.each_with_object({}) do |(target_id, applications), snapshot|
    snapshot[target_id] = applications
  end.freeze
end

#snapshot_attributes ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 116

def snapshot_attributes
  @ctx.attributes.each_with_object({}) do |(name, binding), attributes|
    next if binding.builtin

    attributes[name] = binding
  end.freeze
end

#snapshot_implemented_interfaces ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 136

def snapshot_implemented_interfaces
  @ctx.implemented_interfaces.each_with_object({}) do |(receiver_type, interfaces), snapshot|
    snapshot[receiver_type] = interfaces.dup.freeze
  end.freeze
end

#snapshot_methods ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 130

def snapshot_methods
  @ctx.methods.each_with_object({}) do |(receiver_type, bindings), methods|
    methods[receiver_type] = bindings.dup.freeze
  end.freeze
end

#soa_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 717

def soa_type?(type)
  type.is_a?(Types::SoA)
end

#source_column(node) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 550

def source_column(node)
  return nil unless node
  return node.column if node.column

  case node
  when AST::MemberAccess then source_column(node.receiver)
  when AST::IndexAccess then source_column(node.receiver) || source_column(node.index)
  when AST::Specialization then source_column(node.callee)
  when AST::Call then source_column(node.callee) || node.arguments.filter_map { |argument| source_column(argument.value) }.first
  when AST::Argument then source_column(node.value)
  when AST::UnaryOp then source_column(node.operand)
  when AST::BinaryOp then source_column(node.left) || source_column(node.right)
  when AST::IfExpr then source_column(node.condition) || source_column(node.then_expression) || source_column(node.else_expression)
  when AST::MatchExpr then source_column(node.expression) || node.arms.filter_map { |arm| source_column(arm.pattern) || source_column(arm.value) }.first
  when AST::AwaitExpr then source_column(node.expression)
  when AST::FormatExprPart then source_column(node.expression)
  when AST::PrefixCast then source_column(node.target_type)
  when AST::Assignment then source_column(node.target) || source_column(node.value)
  when AST::ExpressionStmt then source_column(node.expression)
  when AST::StaticAssert then source_column(node.condition)
  when AST::IfStmt then node.branches.filter_map { |branch| branch.column || source_column(branch.condition) }.first || node.else_column
  else nil
  end
end

#source_length(node) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 532

def source_length(node)
  return nil unless node
  return node.length if node.respond_to?(:length) && node.length
  return node.name.to_s.length if node.respond_to?(:name) && node.name

  case node
  when AST::Identifier then node.name.to_s.length
  when AST::MemberAccess then node.member.to_s.length
  when AST::Assignment then source_length(node.target) || source_length(node.value)
  when AST::ExpressionStmt then source_length(node.expression)
  when AST::StaticAssert then source_length(node.condition)
  when AST::IfStmt
    node.branches.filter_map { |branch| branch.length || source_length(branch.condition) }.first
  else
    nil
  end
end

#source_line(node) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 511

def source_line(node)
  return nil unless node
  return node.line if node.line

  case node
  when AST::MemberAccess then source_line(node.receiver)
  when AST::IndexAccess then source_line(node.receiver) || source_line(node.index)
  when AST::Specialization then source_line(node.callee)
  when AST::Call then source_line(node.callee) || node.arguments.filter_map { |argument| source_line(argument.value) }.first
  when AST::Argument then source_line(node.value)
  when AST::UnaryOp then source_line(node.operand)
  when AST::BinaryOp then source_line(node.left) || source_line(node.right)
  when AST::IfExpr then source_line(node.condition) || source_line(node.then_expression) || source_line(node.else_expression)
  when AST::MatchExpr then source_line(node.expression) || node.arms.filter_map { |arm| source_line(arm.pattern) || source_line(arm.value) }.first
  when AST::AwaitExpr then source_line(node.expression)
  when AST::FormatExprPart then source_line(node.expression)
  when AST::PrefixCast then source_line(node.target_type)
  else nil
  end
end

#span_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 576

def span_type?(type)
  type.is_a?(Types::Span)
end

#specialization_lookup_owner ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 123

def specialization_lookup_owner
  return nil if @current_specialization_owner.nil?
  return nil if @current_specialization_owner.equal?(self)

  @current_specialization_owner
end

#specialize_function_binding(binding, arguments, scopes:, receiver_type: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 169

def specialize_function_binding(binding, arguments, scopes:, receiver_type: nil)
  return binding if binding.type_params.empty?

  type_arguments = infer_function_type_arguments(binding, arguments, scopes:, receiver_type:)
  instantiate_function_binding(binding, type_arguments)
end

#stack_safe_pointer_source?(binding) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1422

def stack_safe_pointer_source?(binding)
  return false unless binding.type
  ref_type?(binding.type) || own_type?(binding.type) || (binding.mutable && binding.kind == :param)
end

#start_local_completion_frame(binding, scopes) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 101

def start_local_completion_frame(binding, scopes)
  frame = {
    function_name: binding.name,
    receiver_type: binding.type.receiver_type,
    snapshots: [],
  }
  @active_local_completion_stack << frame
  record_local_completion_snapshot(binding.ast.line, 0, scopes)
end

#statement_contains_await?(statement) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 206

def statement_contains_await?(statement)
  case statement
  when AST::ErrorBlockStmt
    (statement.header_expression && expression_contains_await?(statement.header_expression)) ||
      Array(statement.header_iterables).any? { |iterable| expression_contains_await?(iterable) } ||
      statements_contain_await?(statement.body)
  when AST::LocalDecl
    (statement.value && expression_contains_await?(statement.value)) ||
      (statement.else_body && statements_contain_await?(statement.else_body))
  when AST::Assignment
    expression_contains_await?(statement.target) || expression_contains_await?(statement.value)
  when AST::IfStmt
    statement.branches.any? { |branch| expression_contains_await?(branch.condition) || statements_contain_await?(branch.body) } ||
      (statement.else_body && statements_contain_await?(statement.else_body))
  when AST::MatchStmt
    expression_contains_await?(statement.expression) || statement.arms.any? { |arm| expression_contains_await?(arm.pattern) || statements_contain_await?(arm.body) }
  when AST::UnsafeStmt
    statements_contain_await?(statement.body)
  when AST::StaticAssert
    expression_contains_await?(statement.condition) || expression_contains_await?(statement.message)
  when AST::ForStmt
    statement.iterables.any? { |iterable| expression_contains_await?(iterable) } || statements_contain_await?(statement.body)
  when AST::WhileStmt
    expression_contains_await?(statement.condition) || statements_contain_await?(statement.body)
  when AST::ReturnStmt
    statement.value && expression_contains_await?(statement.value)
  when AST::DeferStmt
    (statement.expression && expression_contains_await?(statement.expression)) || (statement.body && statements_contain_await?(statement.body))
  when AST::ExpressionStmt
    expression_contains_await?(statement.expression)
  else
    false
  end
end

#statement_end_line(statement) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 184

def statement_end_line(statement)
  return nil unless statement

  lines = [statement.line]

  case statement
  when AST::ErrorBlockStmt
    lines.concat(statement_list_lines(statement.body))
  when AST::LocalDecl
    lines << expression_end_line(statement.value) if statement.value
    lines.concat(statement_list_lines(statement.else_body)) if statement.else_body
  when AST::IfStmt
    statement.branches.each do |branch|
      lines << expression_end_line(branch.condition)
      lines.concat(statement_list_lines(branch.body))
    end
    lines.concat(statement_list_lines(statement.else_body)) if statement.else_body
  when AST::UnsafeStmt, AST::ForStmt, AST::WhileStmt
    lines.concat(statement_list_lines(statement.body))
  when AST::MatchStmt
    statement.arms.each do |arm|
      if arm.respond_to?(:body)
        lines.concat(statement_list_lines(arm.body))
      else
        lines << expression_end_line(arm.value)
      end
    end
  when AST::DeferStmt
    lines.concat(statement_list_lines(statement.body)) if statement.body
  when AST::Assignment
    lines << expression_end_line(statement.value)
  when AST::ReturnStmt
    lines << expression_end_line(statement.value)
  when AST::ExpressionStmt
    lines << expression_end_line(statement.expression)
  when AST::StaticAssert
    lines << expression_end_line(statement.condition)
  end

  lines.compact.max
end

#statement_list_lines(statements) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/flow_refinement.rb', line 226

def statement_list_lines(statements)
  return [] unless statements

  statements.each_with_object([]) do |stmt, lines|
    end_line = statement_end_line(stmt)
    lines << end_line if end_line
  end
end

#statements_contain_await?(statements) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 241

def statements_contain_await?(statements)
  statements.any? { |statement| statement_contains_await?(statement) }
end

#static_storage_function_value?(binding) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 183

def static_storage_function_value?(binding)
  !binding.external && binding.type_params.empty?
end

#static_storage_member_initializer?(expression, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 125

def static_storage_member_initializer?(expression, scopes:)
  if (type_expr = resolve_type_expression(expression.receiver))
    return true if resolve_type_member(type_expr, expression.member)
  end

  return false unless expression.receiver.is_a?(AST::Identifier)
  return false unless @ctx.imports.key?(expression.receiver.name)

  imported_module = @ctx.imports.fetch(expression.receiver.name)
  if imported_module.private_value?(expression.member) || imported_module.private_function?(expression.member) || imported_module.private_type?(expression.member)
    raise_sema_error("#{expression.receiver.name}.#{expression.member} is private to module #{imported_module.name}")
  end

  if (binding = imported_module.values[expression.member])
    return true if binding.kind == :const

    raise_sema_error("module variable initializer cannot reference mutable value #{expression.receiver.name}.#{expression.member}")
  end

  function = imported_module.functions[expression.member]
  function && static_storage_function_value?(function)
end

#stored_ref_supported_type?(type, visited = {}, allow_lifetimes: []) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1135

def stored_ref_supported_type?(type, visited = {}, allow_lifetimes: [])
  visitor = StoredRefSupportedVisitor.new(allow_lifetimes:)
  visitor.visit(type)
  visitor.result?
end

#str_buffer_capacity(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 782

def str_buffer_capacity(type)
  type.arguments.first.value
end

#str_buffer_method_kind(receiver_type, name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 775

def str_buffer_method_kind(receiver_type, name)
  return unless str_buffer_type?(receiver_type)

  STR_BUFFER_METHOD_KINDS[name]
end

#str_buffer_method_name(kind) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 781

def str_buffer_method_name(kind)
  STR_BUFFER_METHOD_NAMES.fetch(kind)
end

#str_buffer_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 746

def str_buffer_type?(type)
  type.is_a?(Types::GenericInstance) && type.name == "str_buffer" && type.arguments.length == 1 &&
    generic_integer_type_argument?(type.arguments.first)
end

#string_like_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 918

def string_like_type?(type)
  type == @ctx.types.fetch("str") || type == @ctx.types.fetch("cstr")
end

#string_view_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 580

def string_view_type?(type)
  type.is_a?(Types::StringView)
end

#struct_declaration_for_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1612

def struct_declaration_for_type(type)
  return type.ast_declaration if type.respond_to?(:ast_declaration) && type.ast_declaration

  return nil unless type.respond_to?(:module_name)
  if type.module_name == @ctx.module_name
    return @ctx.ast.declarations.find do |decl|
      decl.is_a?(AST::StructDecl) && decl.name == type.name
    end
  end

  imported_module = imported_module_binding_for_name(type.module_name)
  return nil unless imported_module

  declaration = imported_module.type_declarations[type.name]
  declaration if declaration.is_a?(AST::StructDecl)
end

#struct_handle_for_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1602

def struct_handle_for_type(type)
  base_type = type.is_a?(Types::StructInstance) ? type.definition : type
  return nil unless base_type.is_a?(Types::Struct) || base_type.is_a?(Types::GenericStructDefinition)

  declaration = struct_declaration_for_type(base_type)
  return nil unless declaration

  Types::StructHandle.new(base_type, declaration)
end

#struct_instance_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 843

def struct_instance_type?(type)
  type.is_a?(Types::Struct) || type.is_a?(Types::Variant)
end

#subscription_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 763

def subscription_type?(type)
  type.is_a?(Types::Subscription)
end

#substitute_type(type, substitutions) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 410

def substitute_type(type, substitutions)
  SubstituteTypeVisitor.new(substitutions).apply(type)
end

#substitute_value_binding(binding, substitutions) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 376

def substitute_value_binding(binding, substitutions)
  ValueBinding.new(
    id: binding.id,
    name: binding.name,
    storage_type: substitute_type(binding.storage_type, substitutions),
    flow_type: binding.flow_type ? substitute_type(binding.flow_type, substitutions) : nil,
    mutable: binding.mutable,
    kind: binding.kind,
    const_value: binding.const_value,
  )
end

#suggest_name(wrong, candidates, max_distance: 2) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 274

def suggest_name(wrong, candidates, max_distance: 2)
  return nil if wrong.nil? || wrong.to_s.empty? || candidates.nil? || candidates.empty?

  wrong_str = wrong.to_s
  closest = nil
  closest_dist = max_distance + 1
  candidates.each do |candidate|
    next if candidate.nil?
    cand_str = candidate.to_s
    next if cand_str.empty? || cand_str == wrong_str
    dist = levenshtein(wrong_str, cand_str)
    if dist < closest_dist
      closest_dist = dist
      closest = cand_str
    end
  end
  closest_dist <= max_distance ? closest : nil
end

#top_level_event_receiver?(receiver_expression, scopes:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 726

def top_level_event_receiver?(receiver_expression, scopes:)
  case receiver_expression
  when AST::Identifier
    binding = lookup_value(receiver_expression.name, scopes)
    binding&.kind == :event
  when AST::MemberAccess
    return false unless receiver_expression.receiver.is_a?(AST::Identifier) && @ctx.imports.key?(receiver_expression.receiver.name)

    imported_module = @ctx.imports.fetch(receiver_expression.receiver.name)
    binding = imported_module.values[receiver_expression.member]
    binding && binding.kind == :event
  else
    false
  end
end

#top_level_function(name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 421

def top_level_function(name)
  @ctx.top_level_functions[name]
end

#try_record_generic_local_snapshot(stmt, scopes, binding) ⇒ Object

When a generic method body contains a let/var declaration, always record a completion snapshot so hover and completion can discover the local, even when full type inference is impossible. The inferred type is used when available; otherwise the explicit type annotation on the declaration is consulted. As a last resort a fallback primitive type is used so the binding is never silently dropped.



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 472

def try_record_generic_local_snapshot(stmt, scopes, binding)
  type = infer_local_initializer_type(stmt, scopes) ||
         explicit_declaration_type_for(stmt) ||
         fallback_completion_type

  decl_kind = stmt.kind == :var ? :var : :let
  vb = value_binding(name: stmt.name, type: type, mutable: stmt.kind == :var, kind: decl_kind)
  new_scopes = scopes.dup.unshift({ stmt.name => vb })
  record_local_completion_snapshot(stmt.line, stmt.column, new_scopes)
end

#type_implements_interface?(type, interface) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 164

def type_implements_interface?(type, interface)
  key = interface_implementation_key(type)
  return true if @ctx.implemented_interfaces.fetch(key, []).include?(interface)

  @ctx.imports.each_value do |module_binding|
    return true if module_binding.implemented_interfaces.fetch(key, []).include?(interface)
  end

  false
end

#type_satisfies_interface_constraint?(type, interface, available_type_param_constraints: current_type_param_constraints) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 175

def type_satisfies_interface_constraint?(type, interface, available_type_param_constraints: current_type_param_constraints)
  if type.is_a?(Types::TypeVar)
    constraint = available_type_param_constraints[type.name]
    return constraint && constraint.interfaces.include?(interface)
  end

  type_implements_interface?(type, interface)
end

#typed_null_target_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 329

def typed_null_target_type?(type)
  type == @ctx.types.fetch("cstr") || pointer_type?(type) || function_pointer_type?(type)
end

#types_compatible?(actual_type, expected_type, expression: nil, scopes: nil, external_numeric: false, external_pointer_null: false, contextual_int_to_float: false) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 28

def types_compatible?(actual_type, expected_type, expression: nil, scopes: nil, external_numeric: false, external_pointer_null: false, contextual_int_to_float: false)
  return true if error_type?(actual_type) || error_type?(expected_type)
  return true if actual_type == expected_type
  return true if ref_types_compatible?(actual_type, expected_type)
  return true if null_assignable_to?(actual_type, expected_type)
  return true if external_pointer_null && external_typed_null_pointer_compatibility?(actual_type, expected_type)
  return true if expected_type.is_a?(Types::Nullable) && actual_type == expected_type.base
  return true if mutable_to_const_pointer_compatibility?(actual_type, expected_type)
  return true if own_to_raw_pointer_compatibility?(actual_type, expected_type)
  return true if string_literal_cstr_compatibility?(expression, expected_type)
  return true if exact_compile_time_numeric_compatibility?(actual_type, expression, expected_type, scopes:)
  return true if integer_to_char_compatibility?(actual_type, expected_type) &&
                 (!expression || !scopes || integer_constant_fits_in_char?(expression, scopes))
  return true if lossless_integer_compatibility?(actual_type, expected_type)
  return true if external_numeric && external_numeric_compatibility?(actual_type, expected_type)
  return true if contextual_int_to_float && contextual_int_to_float_compatibility?(actual_type, expected_type) &&
                 (!expression || !scopes || contextual_int_to_float_fits?(expression, expected_type, scopes))
  return true if same_external_opaque_handle_pointer_compatibility?(actual_type, expected_type)
  return true if actual_type.is_a?(Types::Function) && expected_type.is_a?(Types::Function) &&
                 !actual_type.receiver_type && !actual_type.variadic &&
                 function_type_matches_proc_type?(actual_type, expected_type)
  return true if quat_vec4_compatible?(actual_type, expected_type)

  false
end

#unsafe_context? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 82

def unsafe_context?
  @unsafe_depth.positive?
end

#unsupported_async_await_context(expression) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 202

def unsupported_async_await_context(expression)
  nil
end

#validate_async_expression_support!(expression, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 195

def validate_async_expression_support!(expression, context:)
  unsupported_context = unsupported_async_await_context(expression)
  return unless unsupported_context

  raise_sema_error("await in async functions is not supported inside #{unsupported_context} yet")
end

#validate_async_function_body!(statements) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 125

def validate_async_function_body!(statements)
  statements.each { |statement| validate_async_statement!(statement) }
end

#validate_async_statement!(statement) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 129

def validate_async_statement!(statement)
  case statement
  when AST::ErrorBlockStmt
    if statement.header_expression
      context = case statement.header_type
                when :if then "if conditions"
                when :while then "while conditions"
                end
      validate_async_expression_support!(statement.header_expression, context:) if context
    end
    if statement.header_type == :for
      Array(statement.header_iterables).each do |iterable|
        validate_async_expression_support!(iterable, context: "for iterables")
      end
    end
    statement.body.each { |s| validate_async_statement!(s) }
  when AST::ErrorStmt
    nil
  when AST::LocalDecl
    validate_async_expression_support!(statement.value, context: "local initializer") if statement.value
    statement.else_body&.each { |s| validate_async_statement!(s) }
  when AST::Assignment
    validate_async_expression_support!(statement.target, context: "assignment target")
    validate_async_expression_support!(statement.value, context: "assignment")
  when AST::ExpressionStmt
    validate_async_expression_support!(statement.expression, context: "expression statement")
  when AST::ReturnStmt
    return unless statement.value

    validate_async_expression_support!(statement.value, context: "return statement")
  when AST::IfStmt
    statement.branches.each do |branch|
      validate_async_expression_support!(branch.condition, context: "if conditions")

      branch.body.each { |s| validate_async_statement!(s) }
    end
    statement.else_body&.each { |s| validate_async_statement!(s) }
  when AST::WhileStmt
    validate_async_expression_support!(statement.condition, context: "while conditions")

    statement.body.each { |s| validate_async_statement!(s) }
  when AST::ForStmt
    statement.iterables.each do |iterable|
      validate_async_expression_support!(iterable, context: "for iterables")
    end

    statement.body.each { |s| validate_async_statement!(s) }
  when AST::MatchStmt
    validate_async_expression_support!(statement.expression, context: "match discriminants")

    statement.arms.each { |arm| arm.body.each { |s| validate_async_statement!(s) } }
  when AST::UnsafeStmt
    statement.body.each { |s| validate_async_statement!(s) }
  when AST::DeferStmt
    validate_async_expression_support!(statement.expression, context: "defer cleanup") if statement.expression
    statement.body&.each { |s| validate_async_statement!(s) }
  when AST::WhenStmt
    statement.branches.each { |branch| branch.body.each { |s| validate_async_statement!(s) } }
    statement.else_body&.each { |s| validate_async_statement!(s) }
  when AST::BreakStmt, AST::ContinueStmt, AST::StaticAssert, AST::PassStmt
    nil
  else
    raise_sema_error("async functions currently only support straight-line local declarations, assignments, expression statements, and return statements")
  end
end

#validate_attribute_target_compatibility!(target, binding) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1633

def validate_attribute_target_compatibility!(target, binding)
  target_kind = attribute_target_kind(target)
  raise_sema_error("attribute #{qualified_attribute_name(binding)} cannot target #{target_kind}") unless binding.targets.include?(target_kind)
end

#validate_consuming_foreign_expression!(expression, scopes:, root_allowed: false) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1020

def validate_consuming_foreign_expression!(expression, scopes:, root_allowed: false)
  return unless expression
  return if expression.is_a?(AST::ErrorExpr)

  if (foreign_call = resolve_foreign_call_expression(expression, scopes:)) && foreign_call_consumes_binding?(foreign_call[:binding])
    raise_sema_error("consuming foreign calls must be top-level expression statements") unless root_allowed
  end

  case expression
  when AST::Call, AST::Specialization
    validate_consuming_foreign_expression!(expression.callee, scopes:, root_allowed: false)
    expression.arguments.each do |argument|
      validate_consuming_foreign_expression!(argument.value, scopes:, root_allowed: false)
    end
  when AST::UnaryOp
    validate_consuming_foreign_expression!(expression.operand, scopes:, root_allowed: false)
  when AST::BinaryOp
    validate_consuming_foreign_expression!(expression.left, scopes:, root_allowed: false)
    validate_consuming_foreign_expression!(expression.right, scopes:, root_allowed: false)
  when AST::IfExpr
    validate_consuming_foreign_expression!(expression.condition, scopes:, root_allowed: false)
    validate_consuming_foreign_expression!(expression.then_expression, scopes:, root_allowed: false)
    validate_consuming_foreign_expression!(expression.else_expression, scopes:, root_allowed: false)
  when AST::MatchExpr
    validate_consuming_foreign_expression!(expression.expression, scopes:, root_allowed: false)
    expression.arms.each do |arm|
      validate_consuming_foreign_expression!(arm.pattern, scopes:, root_allowed: false)
      arm_scopes = arm.binding_name ? scopes + [{ arm.binding_name => value_binding(name: arm.binding_name, type: @error_type, mutable: false, kind: :local, id: @preassigned_local_binding_ids.fetch(arm.object_id)) }] : scopes
      validate_consuming_foreign_expression!(arm.value, scopes: arm_scopes, root_allowed: false)
    end
  when AST::UnsafeExpr
    validate_consuming_foreign_expression!(expression.expression, scopes:, root_allowed: false)
  when AST::FormatString
    expression.parts.each do |part|
      next unless part.is_a?(AST::FormatExprPart)

      validate_consuming_foreign_expression!(part.expression, scopes:, root_allowed: false)
    end
  when AST::MemberAccess
    validate_consuming_foreign_expression!(expression.receiver, scopes:, root_allowed: false)
  when AST::IndexAccess
    validate_consuming_foreign_expression!(expression.receiver, scopes:, root_allowed: false)
    validate_consuming_foreign_expression!(expression.index, scopes:, root_allowed: false)
  when AST::RangeExpr
    validate_consuming_foreign_expression!(expression.start_expr, scopes:, root_allowed: false)
    validate_consuming_foreign_expression!(expression.end_expr, scopes:, root_allowed: false)
  when AST::PrefixCast
    validate_consuming_foreign_expression!(expression.expression, scopes:, root_allowed: false)
  end
end

#validate_consuming_foreign_parameter!(type, function_name:, parameter_name:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 6

def validate_consuming_foreign_parameter!(type, function_name:, parameter_name:)
  if type.is_a?(Types::Nullable) || !(opaque_type?(type) || pointer_type?(type))
    raise_sema_error("consuming parameter #{parameter_name} of #{function_name} must use a non-null opaque or ptr[...] type")
  end
end

#validate_detach_argument!(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 716

def validate_detach_argument!(expression, scopes:)
  return true if expression.is_a?(AST::IntegerLiteral) || expression.is_a?(AST::FloatLiteral) ||
    expression.is_a?(AST::StringLiteral) || expression.is_a?(AST::BooleanLiteral) ||
    expression.is_a?(AST::NullLiteral) || expression.is_a?(AST::CharLiteral) ||
    expression.is_a?(AST::FormatString)

  if expression.is_a?(AST::Identifier)
    binding = lookup_value(expression.name, scopes)
    return true unless binding && %i[let var param].include?(binding.kind)

    raise_sema_error("detach argument cannot capture local variable #{expression.name}")
  end

  true
end

#validate_detach_expression!(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 705

def validate_detach_expression!(expression, scopes:)
  case expression
  when AST::Call, AST::Specialization
    expression.arguments.each do |arg|
      validate_detach_argument!(arg.value, scopes:)
    end
  else
    raise_sema_error("detach currently only supports global function calls")
  end
end

#validate_explicit_aggregate_c_name!(decl) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 417

def validate_explicit_aggregate_c_name!(decl)
  return unless decl.c_name

  raise_sema_error("explicit C names are only allowed on external structs and unions") unless raw_module?
  return if !decl.respond_to?(:type_params) || decl.type_params.empty?

  raise_sema_error("explicit C names are not supported on generic external structs")
end

#validate_foreign_boundary_type!(public_type, boundary_type, function_name:, parameter_name:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 69

def validate_foreign_boundary_type!(public_type, boundary_type, function_name:, parameter_name:)
  return if boundary_type == public_type
  return if boundary_type == @ctx.types.fetch("cstr") && public_type == @ctx.types.fetch("str")
  return if foreign_span_boundary_compatible?(public_type, boundary_type)
  return if foreign_char_pointer_buffer_boundary_compatible?(public_type, boundary_type)
  return if foreign_identity_projection_compatible?(public_type, boundary_type)

  raise_sema_error("foreign parameter #{parameter_name} of #{function_name} cannot map #{public_type} as #{boundary_type}")
end

#validate_function_type_param_constraints!(binding, substitutions) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 246

def validate_function_type_param_constraints!(binding, substitutions)
  binding.type_param_constraints.each do |name, constraints|
    actual_type = substitutions[name]
    raise_sema_error("cannot infer type argument #{name} for function #{binding.name}") unless actual_type

    validate_type_param_constraint_binding!(constraints, actual_type, context: "function #{binding.name}")
  end
end

#validate_generic_type!(name, arguments) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 835

def validate_generic_type!(name, arguments)
  super(name, arguments) { |msg| raise_sema_error(msg) }
end

#validate_generic_type_param_constraints!(generic_type, arguments, context:, available_type_param_constraints: current_type_param_constraints) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 192

def validate_generic_type_param_constraints!(generic_type, arguments, context:, available_type_param_constraints: current_type_param_constraints)
  return if generic_type.type_param_constraints.empty?

  generic_type.type_params.zip(arguments).each do |name, actual_type|
    constraints = generic_type.type_param_constraints[name]
    next unless constraints

    validate_type_param_constraint_binding!(constraints, actual_type, context:, available_type_param_constraints:)
  end
end

#validate_hash_operation_argument!(expression, target_type, scopes:, operation:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/calls.rb', line 456

def validate_hash_operation_argument!(expression, target_type, scopes:, operation:)
  actual_type = infer_expression(expression, scopes:)
  expected_pointer_type = const_pointer_to(target_type)
  return if argument_types_compatible?(actual_type, expected_pointer_type, external: false, expression:, scopes:)
  return if ref_type?(actual_type) && types_compatible?(referenced_type(actual_type), target_type, expression:, scopes:)
  return if safe_reference_source_expression?(expression, scopes:) && types_compatible?(actual_type, target_type, expression:, scopes:)

  raise_sema_error("#{operation}[#{target_type}] expects a safe #{target_type} lvalue, ref[#{target_type}], ptr[#{target_type}], or const_ptr[#{target_type}], got #{actual_type}")
end

#validate_hoistable_foreign_expression!(expression, scopes:, root_hoistable: false) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/expressions.rb', line 1071

def validate_hoistable_foreign_expression!(expression, scopes:, root_hoistable: false)
  return unless expression
  return if expression.is_a?(AST::ErrorExpr)

  if (foreign_call = resolve_foreign_call_expression(expression, scopes:)) && (message = inline_foreign_call_requires_hoisting_message(foreign_call, scopes:))
    raise_sema_error(message) unless root_hoistable
  end

  case expression
  when AST::Call, AST::Specialization
    validate_hoistable_foreign_expression!(expression.callee, scopes:, root_hoistable: false)
    expression.arguments.each do |argument|
      validate_hoistable_foreign_expression!(argument.value, scopes:, root_hoistable: false)
    end
  when AST::UnaryOp
    validate_hoistable_foreign_expression!(expression.operand, scopes:, root_hoistable: false)
  when AST::BinaryOp
    validate_hoistable_foreign_expression!(expression.left, scopes:, root_hoistable: false)
    validate_hoistable_foreign_expression!(expression.right, scopes:, root_hoistable: false)
  when AST::IfExpr
    validate_hoistable_foreign_expression!(expression.condition, scopes:, root_hoistable: false)
    validate_hoistable_foreign_expression!(expression.then_expression, scopes:, root_hoistable: false)
    validate_hoistable_foreign_expression!(expression.else_expression, scopes:, root_hoistable: false)
  when AST::MatchExpr
    validate_hoistable_foreign_expression!(expression.expression, scopes:, root_hoistable: false)
    expression.arms.each do |arm|
      validate_hoistable_foreign_expression!(arm.pattern, scopes:, root_hoistable: false)
      arm_scopes = arm.binding_name ? scopes + [{ arm.binding_name => value_binding(name: arm.binding_name, type: @error_type, mutable: false, kind: :local, id: @preassigned_local_binding_ids.fetch(arm.object_id)) }] : scopes
      validate_hoistable_foreign_expression!(arm.value, scopes: arm_scopes, root_hoistable: false)
    end
  when AST::UnsafeExpr
    validate_hoistable_foreign_expression!(expression.expression, scopes:, root_hoistable: false)
  when AST::FormatString
    expression.parts.each do |part|
      next unless part.is_a?(AST::FormatExprPart)

      validate_hoistable_foreign_expression!(part.expression, scopes:, root_hoistable: false)
    end
  when AST::MemberAccess
    validate_hoistable_foreign_expression!(expression.receiver, scopes:, root_hoistable: false)
  when AST::IndexAccess
    validate_hoistable_foreign_expression!(expression.receiver, scopes:, root_hoistable: false)
    validate_hoistable_foreign_expression!(expression.index, scopes:, root_hoistable: false)
  when AST::RangeExpr
    validate_hoistable_foreign_expression!(expression.start_expr, scopes:, root_hoistable: false)
    validate_hoistable_foreign_expression!(expression.end_expr, scopes:, root_hoistable: false)
  when AST::PrefixCast
    validate_hoistable_foreign_expression!(expression.expression, scopes:, root_hoistable: false)
  end
end

#validate_in_foreign_parameter!(public_type, boundary_type, function_name:, parameter_name:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/foreign_functions.rb', line 52

def validate_in_foreign_parameter!(public_type, boundary_type, function_name:, parameter_name:)
  unless const_pointer_type?(boundary_type)
    raise_sema_error("in parameter #{parameter_name} of #{function_name} must lower to const_ptr[...], got #{boundary_type || public_type}")
  end

  expected_public_type = pointee_type(boundary_type)
  return if expected_public_type == public_type
  return if expected_public_type == @ctx.types.fetch("void")
  return if foreign_identity_projection_compatible?(public_type, expected_public_type)

  raise_sema_error("in parameter #{parameter_name} of #{function_name} cannot map #{public_type} as #{boundary_type}")
end

#validate_local_proc_type!(type, local_name, initializer:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1209

def validate_local_proc_type!(type, local_name, initializer:)
  return unless contains_proc_type?(type)

  raise_sema_error("local #{local_name} uses unsupported proc nesting") unless proc_storage_supported_type?(type)
end

#validate_local_ref_type!(type, local_name) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1195

def validate_local_ref_type!(type, local_name)
  return if ref_type?(type)
  return if (type.is_a?(Types::Struct) || type.is_a?(Types::StructInstance)) && type.fields.any? && contains_ref_type?(type)
  return if stored_ref_supported_type?(type)

  if contains_ref_type?(type)
    if callable_type?(type) || contains_callable_ref_type?(type)
      raise_sema_error("local #{local_name} cannot store ref types outside callable parameter positions")
    end

    raise_sema_error("local #{local_name} cannot store nested ref types")
  end
end

#validate_methods_receiver_type_arguments!(type_ref, generic_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1075

def validate_methods_receiver_type_arguments!(type_ref, generic_type)
  names = type_ref.arguments.map do |argument|
    value = argument.value
    next unless value.is_a?(AST::TypeRef)
    next unless value.arguments.empty? && !value.nullable && value.name.parts.length == 1

    value.name.parts.first
  end

  expected_names = generic_type.type_params
  unless names == expected_names
    raise_sema_error("extending target #{type_ref} must use the receiver type parameters directly")
  end

  expected_names
end

#validate_parameter_proc_type!(type, function_name:, parameter_name:, external:, foreign:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1172

def validate_parameter_proc_type!(type, function_name:, parameter_name:, external:, foreign:)
  if contains_proc_type?(type)
    raise_sema_error("external function #{function_name} cannot take proc parameters") if external
    raise_sema_error("foreign function #{function_name} cannot take proc parameters") if foreign
    raise_sema_error("parameter #{parameter_name} of #{function_name} uses unsupported proc nesting") unless proc_storage_supported_type?(type)
  end
end

#validate_parameter_ref_type!(type, function_name:, parameter_name:, external:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1160

def validate_parameter_ref_type!(type, function_name:, parameter_name:, external:)
  if ref_type?(type)
    raise_sema_error("external function #{function_name} cannot take ref parameters") if external

    return
  end

  return if callable_param_ref_supported?(type)

  raise_sema_error("parameter #{parameter_name} of #{function_name} cannot nest ref types") if contains_ref_type?(type)
end

#validate_read_call_arguments!(arguments) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1295

def validate_read_call_arguments!(arguments)
  raise_sema_error("read does not support named arguments") if arguments.any?(&:name)
  raise_sema_error("read expects 1 argument, got #{arguments.length}") unless arguments.length == 1
end

#validate_return_proc_type!(type, function_name:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1189

def validate_return_proc_type!(type, function_name:)
  if contains_proc_type?(type)
    raise_sema_error("function #{function_name} uses unsupported proc nesting in return type") unless proc_storage_supported_type?(type)
  end
end

#validate_return_ref_type!(type, function_name:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1180

def validate_return_ref_type!(type, function_name:)
  if contains_ref_type?(type)
    if (type.is_a?(Types::Struct) || type.is_a?(Types::StructInstance)) && type.fields.any?
      raise_sema_error("function #{function_name} cannot return non-owning struct #{type.name} (contains borrowed ref)")
    end
    raise_sema_error("function #{function_name} cannot return ref types")
  end
end

#validate_specialized_function_binding!(function_name, function_type, body_params) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 388

def validate_specialized_function_binding!(function_name, function_type, body_params)
  function_type.params.each do |param|
    validate_specialized_function_type!(param.type, function_name:, context: "parameter #{param.name}")
    validate_specialized_function_type!(param.boundary_type, function_name:, context: "boundary parameter #{param.name}") if param.boundary_type
  end
  validate_specialized_function_type!(function_type.return_type, function_name:, context: "return type")
  validate_specialized_function_type!(function_type.receiver_type, function_name:, context: "receiver type") if function_type.receiver_type

  body_params.each do |param|
    validate_specialized_function_type!(param.type, function_name:, context: "body parameter #{param.name}")
  end
end

#validate_specialized_function_body(binding) ⇒ Object

Validates the body of a specialized (instantiated) function or method binding. The owner checker may be in collecting-errors mode, which would silently swallow body errors into @structural_errors. We temporarily disable collect mode on the owner so the caller receives the SemanticError directly.



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# File 'lib/milk_tea/core/semantic_analyzer/function_binding.rb', line 269

def validate_specialized_function_body(binding)
  owner = binding.owner
  prev_collecting = owner.instance_variable_get(:@collecting_errors)
  owner.instance_variable_set(:@collecting_errors, false)
  owner.check_function(binding)
rescue SemanticError => e
  raise unless e.message.include?("cannot assign through immutable")
ensure
  owner.instance_variable_set(:@collecting_errors, prev_collecting) if owner
end

#validate_specialized_function_type!(type, function_name:, context:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/generics.rb', line 401

def validate_specialized_function_type!(type, function_name:, context:)
  ValidateSpecializedTypeVisitor.new(
    function_name:,
    context:,
    on_error: ->(msg) { raise_sema_error(msg) },
    on_generic_instance: ->(name, args) { validate_generic_type!(name, args) },
  ).visit(type)
end

#validate_static_storage_call_initializer!(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 148

def validate_static_storage_call_initializer!(expression, scopes:)
  expression.arguments.each do |argument|
    validate_static_storage_initializer!(argument.value, scopes:)
  end

  callee = expression.callee
  if callee.is_a?(AST::Identifier)
    if (type_expr = resolve_type_expression(callee))
      return if type_expr.is_a?(Types::Struct) || type_expr.is_a?(Types::StringView)
    end
  end

  if callee.is_a?(AST::MemberAccess)
    if (type_expr = resolve_type_expression(callee))
      return if type_expr.is_a?(Types::Struct) || type_expr.is_a?(Types::StringView)
    end
  end

  if callee.is_a?(AST::Specialization)
    if callee.callee.is_a?(AST::Identifier)
      case callee.callee.name
      when "array", "span", "zero", "reinterpret"
        return
      end
    end

    if (type_ref = type_ref_from_specialization(callee))
      specialized_type = resolve_type_ref(type_ref)
      return if specialized_type.is_a?(Types::Struct) || result_type?(specialized_type)
    end
  end

  raise_sema_error("module variable initializer must be static-storage-safe")
end

#validate_static_storage_initializer!(expression, scopes:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/top_level.rb', line 69

def validate_static_storage_initializer!(expression, scopes:)
  case expression
  when AST::ErrorExpr
    return
  when AST::IntegerLiteral, AST::FloatLiteral, AST::StringLiteral, AST::BooleanLiteral, AST::NullLiteral,
       AST::SizeofExpr, AST::AlignofExpr, AST::OffsetofExpr
    return
  when AST::Identifier
    if (binding = lookup_value(expression.name, scopes))
      return if binding.kind == :const

      raise_sema_error("module variable initializer cannot reference mutable value #{expression.name}")
    end

    function = @ctx.top_level_functions[expression.name]
    return if function && static_storage_function_value?(function)

    raise_sema_error("module variable initializer must be static-storage-safe")
  when AST::MemberAccess
    return if static_storage_member_initializer?(expression, scopes:)

    raise_sema_error("module variable initializer must be static-storage-safe")
  when AST::UnaryOp
    validate_static_storage_initializer!(expression.operand, scopes:)
  when AST::BinaryOp
    validate_static_storage_initializer!(expression.left, scopes:)
    validate_static_storage_initializer!(expression.right, scopes:)
  when AST::IfExpr
    validate_static_storage_initializer!(expression.condition, scopes:)
    validate_static_storage_initializer!(expression.then_expression, scopes:)
    validate_static_storage_initializer!(expression.else_expression, scopes:)
  when AST::UnsafeExpr
    validate_static_storage_initializer!(expression.expression, scopes:)
  when AST::ExpressionList
    expression.elements.each { |element| validate_static_storage_initializer!(element, scopes:) }
  when AST::Specialization
    if expression.callee.is_a?(AST::Identifier)
      return if expression.callee.name == "zero"
    end

    raise_sema_error("module variable initializer must be static-storage-safe")
  when AST::Call
    validate_static_storage_call_initializer!(expression, scopes:)
  when AST::ProcExpr
    # Proc expressions are static-storage-safe when their body only
    # references module-level constants, functions, types, and imports.
    # The lowering handles capture detection; if a proc truly captures
    # a local from an enclosing scope (impossible at module level),
    # the sema validation above already rejects it via the
    # "cannot reference mutable value" check on the proc body.
    return
  else
    raise_sema_error("module variable initializer must be static-storage-safe")
  end
end

#validate_stored_ref_type!(type, context, allow_lifetimes: []) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1120

def validate_stored_ref_type!(type, context, allow_lifetimes: [])
  return unless contains_ref_type?(type, allow_lifetimes:)
  return if stored_ref_supported_type?(type, allow_lifetimes:)

  if callable_type?(type) || contains_callable_ref_type?(type)
    raise_sema_error("#{context} cannot store ref types outside callable parameter positions")
  end

  if context.start_with?("field ")
    raise_sema_error("#{context} cannot store ref types; declare a lifetime on the struct and use ref[@lt, T] (e.g. struct MyStruct[@a]: field: ref[@a, SomeType])")
  end

  raise_sema_error("#{context} cannot store ref types")
end

#validate_struct_layout!(decl) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_declaration.rb', line 408

def validate_struct_layout!(decl)
  return unless decl.alignment

  raise_sema_error("align(...) requires a positive alignment") unless decl.alignment.positive?
  return if power_of_two?(decl.alignment)

  raise_sema_error("align(...) requires a power-of-two alignment, got #{decl.alignment}")
end

#validate_threaded_for_body!(body) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1145

def validate_threaded_for_body!(body)
  body.each { |stmt| validate_threaded_for_statement!(stmt) }
end

#validate_threaded_for_statement!(stmt) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1149

def validate_threaded_for_statement!(stmt)
  case stmt
  when AST::BreakStmt
    raise_sema_error("break is not allowed inside parallel for", line: stmt.line, column: stmt.column)
  when AST::ContinueStmt
    raise_sema_error("continue is not allowed inside parallel for", line: stmt.line, column: stmt.column)
  when AST::ReturnStmt
    raise_sema_error("return is not allowed inside parallel for", line: stmt.line, column: stmt.column)
  when AST::DeferStmt
    raise_sema_error("defer is not allowed inside parallel for", line: stmt.line, column: stmt.column)
  when AST::AwaitExpr
    raise_sema_error("await is not allowed inside parallel for", line: stmt.line, column: stmt.column)
  when AST::IfStmt
    validate_threaded_for_body!(stmt.then_body)
    stmt.else_if_clauses&.each { |clause| validate_threaded_for_body!(clause.body) }
    validate_threaded_for_body!(stmt.else_body) if stmt.else_body
  when AST::WhileStmt
    validate_threaded_for_body!(stmt.body)
  when AST::ForStmt
    raise_sema_error("nested for loops are not allowed inside parallel for", line: stmt.line, column: stmt.column) if stmt.threaded
    validate_threaded_for_body!(stmt.body)
  when AST::MatchStmt
    stmt.arms&.each { |arm| validate_threaded_for_body!(arm.body) }
  when AST::UnsafeStmt
    validate_threaded_for_body!(stmt.body) if stmt.body.is_a?(Array)
  end
end

#validate_type_param_constraint_binding!(constraints, actual_type, context:, available_type_param_constraints: current_type_param_constraints) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 184

def validate_type_param_constraint_binding!(constraints, actual_type, context:, available_type_param_constraints: current_type_param_constraints)
  constraints.interfaces.each do |interface|
    next if type_satisfies_interface_constraint?(actual_type, interface, available_type_param_constraints:)

    raise_sema_error("type #{actual_type} does not implement interface #{interface.name} for #{context}")
  end
end

#value_binding(name:, type:, mutable:, kind:, flow_type: nil, const_value: nil, id: nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 1362

def value_binding(name:, type:, mutable:, kind:, flow_type: nil, const_value: nil, id: nil)
  id ||= allocate_binding_id
  @binding_name_by_id[id] = name
  @binding_type_by_id[id] = flow_type == type ? type : (flow_type || type)
  ValueBinding.new(id:, name:, storage_type: type, flow_type: flow_type == type ? nil : flow_type, mutable:, kind:, const_value:)
end

#variant_match_arm_name(pattern, scrutinee_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 936

def variant_match_arm_name(pattern, scrutinee_type)
  # Pattern must be `TypeName.arm_name` or `module.TypeName.arm_name`
  # For struct patterns, the pattern is Call(MemberAccess(...), args) — unwrap the callee
  callee = case pattern
           when AST::Call
             pattern.callee
           else
             pattern
           end
  return nil unless callee.is_a?(AST::MemberAccess)

  member = callee.member
  return nil unless scrutinee_type.arm_names.include?(member)

  # Verify the receiver resolves to the scrutinee variant type
  receiver_type = resolve_type_expression(callee.receiver)
  return member if receiver_type == scrutinee_type

  if scrutinee_type.is_a?(Types::VariantInstance) && receiver_type.is_a?(Types::GenericVariantDefinition)
    return member if receiver_type == scrutinee_type.definition
  end

  return nil unless scrutinee_type.is_a?(Types::VariantInstance) && receiver_type.is_a?(Types::Variant)
  return nil unless receiver_type.name == scrutinee_type.name && receiver_type.module_name == scrutinee_type.module_name

  member
end

#vector_arithmetic_result(operator, left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 215

def vector_arithmetic_result(operator, left_type, right_type)
  return vector_op_result(operator, left_type, right_type) if vector_type?(left_type) || vector_type?(right_type)
  return matrix_op_result(operator, left_type, right_type) if matrix_type?(left_type) || matrix_type?(right_type)
  return quaternion_op_result(operator, left_type, right_type) if quaternion_type?(left_type) || quaternion_type?(right_type)
  return simd_op_result(operator, left_type, right_type) if simd_type?(left_type) || simd_type?(right_type)

  nil
end

#vector_op_result(operator, left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 260

def vector_op_result(operator, left_type, right_type)
  if vector_type?(left_type) && vector_type?(right_type) && left_type.element_type == right_type.element_type
    return left_type if operator == "+" || operator == "-"
    return left_type if operator == "*"
  end

  if vector_type?(left_type) && right_type.numeric?
    return left_type if operator == "*" || operator == "/"
  end

  if left_type.numeric? && vector_type?(right_type) && operator == "*"
    return right_type
  end

  nil
end

#vector_type?(type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 705

def vector_type?(type)
  type.is_a?(Types::Vector)
end

#walk_assignment_target_reads_for_precheck_resolution(target, operator, scopes, identifier_ids, declaration_ids = nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 389

def walk_assignment_target_reads_for_precheck_resolution(target, operator, scopes, identifier_ids, declaration_ids = nil)
  if operator != "=" && target.is_a?(AST::Identifier)
    if (binding_id = resolve_name_in_precheck_scopes(target.name, scopes))
      identifier_ids[target.object_id] = binding_id
    end
  end

  case target
  when AST::Identifier
    nil
  when AST::MemberAccess
    walk_expression_for_precheck_resolution(target.receiver, scopes, identifier_ids, declaration_ids)
  when AST::IndexAccess
    walk_expression_for_precheck_resolution(target.receiver, scopes, identifier_ids, declaration_ids)
    walk_expression_for_precheck_resolution(target.index, scopes, identifier_ids, declaration_ids)
  else
    walk_expression_for_precheck_resolution(target, scopes, identifier_ids, declaration_ids)
  end
end

#walk_expression_for_precheck_resolution(expression, scopes, identifier_ids, declaration_ids = nil) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 334

def walk_expression_for_precheck_resolution(expression, scopes, identifier_ids, declaration_ids = nil)
  case expression
  when nil
    nil
  when AST::Identifier
    if (binding_id = resolve_name_in_precheck_scopes(expression.name, scopes))
      identifier_ids[expression.object_id] = binding_id
    end
  when AST::MemberAccess
    walk_expression_for_precheck_resolution(expression.receiver, scopes, identifier_ids, declaration_ids)
  when AST::IndexAccess
    walk_expression_for_precheck_resolution(expression.receiver, scopes, identifier_ids, declaration_ids)
    walk_expression_for_precheck_resolution(expression.index, scopes, identifier_ids, declaration_ids)
  when AST::Specialization
    walk_expression_for_precheck_resolution(expression.callee, scopes, identifier_ids, declaration_ids)
  when AST::Call
    walk_expression_for_precheck_resolution(expression.callee, scopes, identifier_ids, declaration_ids)
    expression.arguments.each { |argument| walk_expression_for_precheck_resolution(argument.value, scopes, identifier_ids, declaration_ids) }
  when AST::UnaryOp
    walk_expression_for_precheck_resolution(expression.operand, scopes, identifier_ids, declaration_ids)
  when AST::BinaryOp
    walk_expression_for_precheck_resolution(expression.left, scopes, identifier_ids, declaration_ids)
    walk_expression_for_precheck_resolution(expression.right, scopes, identifier_ids, declaration_ids)
  when AST::RangeExpr
    walk_expression_for_precheck_resolution(expression.start_expr, scopes, identifier_ids, declaration_ids)
    walk_expression_for_precheck_resolution(expression.end_expr, scopes, identifier_ids, declaration_ids)
  when AST::IfExpr
    walk_expression_for_precheck_resolution(expression.condition, scopes, identifier_ids, declaration_ids)
    walk_expression_for_precheck_resolution(expression.then_expression, scopes, identifier_ids, declaration_ids)
    walk_expression_for_precheck_resolution(expression.else_expression, scopes, identifier_ids, declaration_ids)
  when AST::MatchExpr
    walk_expression_for_precheck_resolution(expression.expression, scopes, identifier_ids, declaration_ids)
    expression.arms.each do |arm|
      walk_expression_for_precheck_resolution(arm.pattern, scopes, identifier_ids, declaration_ids)
      arm_scopes = scopes
      if arm.binding_name
        binding_id = @preassigned_local_binding_ids.fetch(arm.object_id)
        arm_scopes = scopes + [{ arm.binding_name => binding_id }]
        declaration_ids[arm.object_id] = binding_id if declaration_ids
      end
      walk_expression_for_precheck_resolution(if arm.respond_to?(:value) then arm.value else arm.body end, arm_scopes, identifier_ids, declaration_ids)
    end
  when AST::UnsafeExpr
    walk_expression_for_precheck_resolution(expression.expression, scopes, identifier_ids, declaration_ids)
  when AST::AwaitExpr
    walk_expression_for_precheck_resolution(expression.expression, scopes, identifier_ids, declaration_ids)
  when AST::FormatString
    expression.parts.each do |part|
      next unless part.is_a?(AST::FormatExprPart)

      walk_expression_for_precheck_resolution(part.expression, scopes, identifier_ids, declaration_ids)
    end
  end
end

#walk_statements_for_precheck_resolution(statements, scopes, declaration_ids, identifier_ids) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/nullability.rb', line 246

def walk_statements_for_precheck_resolution(statements, scopes, declaration_ids, identifier_ids)
  block_scopes = scopes + [{}]
  statements.each do |statement|
    case statement
    when AST::ErrorBlockStmt
      if statement.header_type == :for
        Array(statement.header_iterables).each do |iterable|
          walk_expression_for_precheck_resolution(iterable, block_scopes, identifier_ids, declaration_ids)
        end
        for_scopes = block_scopes + [{}]
        Array(statement.header_bindings).each do |binding|
          binding_id = @preassigned_local_binding_ids.fetch(binding.object_id)
          for_scopes.last[binding.name] = binding_id
          declaration_ids[binding.object_id] = binding_id
        end
        walk_statements_for_precheck_resolution(statement.body || [], for_scopes, declaration_ids, identifier_ids)
      else
        walk_expression_for_precheck_resolution(statement.header_expression, block_scopes, identifier_ids, declaration_ids) if statement.header_expression
        walk_statements_for_precheck_resolution(statement.body || [], block_scopes, declaration_ids, identifier_ids)
      end
    when AST::LocalDecl
      walk_expression_for_precheck_resolution(statement.value, block_scopes, identifier_ids, declaration_ids) if statement.value
      if statement.else_binding && (statement.else_body || statement.recovered_else)
        else_scopes = block_scopes + [{}]
        binding_id = @preassigned_local_binding_ids.fetch(statement.else_binding.object_id)
        else_scopes.last[statement.else_binding.name] = binding_id
        declaration_ids[statement.else_binding.object_id] = binding_id
        walk_statements_for_precheck_resolution(statement.else_body || [], else_scopes, declaration_ids, identifier_ids)
      else
        walk_statements_for_precheck_resolution(statement.else_body || [], block_scopes, declaration_ids, identifier_ids)
      end
      binding_id = @preassigned_local_binding_ids.fetch(statement.object_id)
      unless let_else_discard_binding_syntax?(statement)
        block_scopes.last[statement.name] = binding_id
        declaration_ids[statement.object_id] = binding_id
      end
    when AST::Assignment
      walk_expression_for_precheck_resolution(statement.value, block_scopes, identifier_ids, declaration_ids)
      walk_assignment_target_reads_for_precheck_resolution(statement.target, statement.operator, block_scopes, identifier_ids, declaration_ids)
      if statement.target.is_a?(AST::Identifier)
        if (binding_id = resolve_name_in_precheck_scopes(statement.target.name, block_scopes))
          identifier_ids[statement.target.object_id] = binding_id
        end
      end
    when AST::IfStmt
      statement.branches.each do |branch|
        walk_expression_for_precheck_resolution(branch.condition, block_scopes, identifier_ids, declaration_ids)
        walk_statements_for_precheck_resolution(branch.body || [], block_scopes, declaration_ids, identifier_ids)
      end
      walk_statements_for_precheck_resolution(statement.else_body || [], block_scopes, declaration_ids, identifier_ids)
    when AST::MatchStmt
      walk_expression_for_precheck_resolution(statement.expression, block_scopes, identifier_ids, declaration_ids)
      statement.arms.each do |arm|
        arm_scopes = block_scopes + [{}]
        if arm.binding_name
          binding_id = @preassigned_local_binding_ids.fetch(arm.object_id)
          arm_scopes.last[arm.binding_name] = binding_id
          declaration_ids[arm.object_id] = binding_id
        end
        walk_statements_for_precheck_resolution(if arm.respond_to?(:body) then (arm.body || []) else [arm.value].compact end, arm_scopes, declaration_ids, identifier_ids)
      end
    when AST::UnsafeStmt, AST::WhileStmt
      walk_expression_for_precheck_resolution(statement.condition, block_scopes, identifier_ids, declaration_ids) if statement.is_a?(AST::WhileStmt)
      walk_statements_for_precheck_resolution(statement.body || [], block_scopes, declaration_ids, identifier_ids)
    when AST::ForStmt
      statement.iterables.each do |iterable|
        walk_expression_for_precheck_resolution(iterable, block_scopes, identifier_ids, declaration_ids)
      end
      for_scopes = block_scopes + [{}]
      statement.bindings.each do |binding|
        binding_id = @preassigned_local_binding_ids.fetch(binding.object_id)
        for_scopes.last[binding.name] = binding_id
        declaration_ids[binding.object_id] = binding_id
      end
      walk_statements_for_precheck_resolution(statement.body || [], for_scopes, declaration_ids, identifier_ids)
    when AST::DeferStmt
      walk_expression_for_precheck_resolution(statement.expression, block_scopes, identifier_ids, declaration_ids) if statement.expression
      walk_statements_for_precheck_resolution(statement.body || [], block_scopes, declaration_ids, identifier_ids) if statement.body
    when AST::ExpressionStmt
      walk_expression_for_precheck_resolution(statement.expression, block_scopes, identifier_ids, declaration_ids)
    when AST::ReturnStmt
      walk_expression_for_precheck_resolution(statement.value, block_scopes, identifier_ids, declaration_ids) if statement.value
    when AST::StaticAssert
      walk_expression_for_precheck_resolution(statement.condition, block_scopes, identifier_ids, declaration_ids)
    end
  end
end

#when_chosen_body(decl) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 1239

def when_chosen_body(decl)
  discriminant_value = evaluate_compile_time_const_value(decl.discriminant, scopes: [])
  return nil if discriminant_value.nil?

  chosen_branch = decl.branches.find do |branch|
    pattern_value = evaluate_compile_time_const_value(branch.pattern, scopes: [])
    discriminant_value == pattern_value
  end

  chosen_branch&.body || decl.else_body
end

#wider_float_type(left_type, right_type) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/type_compatibility.rb', line 195

def wider_float_type(left_type, right_type)
  left_type.float_width >= right_type.float_width ? left_type : right_type
end

#wildcard_pattern?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/statements.rb', line 773

def wildcard_pattern?(expression)
  expression.is_a?(AST::Identifier) && expression.name == "_"
end

#with_async_function ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 41

def with_async_function
  @async_function_depth += 1
  yield
ensure
  @async_function_depth -= 1
end

#with_compile_time ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 55

def with_compile_time
  @compile_time_depth += 1
  yield
ensure
  @compile_time_depth -= 1
end

#with_error_node(node) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 492

def with_error_node(node)
  @error_node_stack << node
  yield
ensure
  @error_node_stack.pop
end

#with_foreign_mapping_context ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 34

def with_foreign_mapping_context
  @foreign_mapping_depth += 1
  yield
ensure
  @foreign_mapping_depth -= 1
end

#with_loop ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 48

def with_loop
  @loop_depth += 1
  yield
ensure
  @loop_depth -= 1
end

#with_loop_barrier ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 74

def with_loop_barrier
  previous_loop_depth = @loop_depth
  @loop_depth = 0
  yield
ensure
  @loop_depth = previous_loop_depth
end

#with_nested_scope(scopes) {|nested_scopes| ... } ⇒ Object

Yields:

  • (nested_scopes) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 120

def with_nested_scope(scopes)
  nested_scopes = scopes + [{}]
  yield(nested_scopes)
end

#with_return_context(return_type, allow_return:) ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 98

def with_return_context(return_type, allow_return:)
  @return_context_stack << { return_type:, allow_return: }
  yield
ensure
  @return_context_stack.pop
end

#with_scope(bindings) {|[scope]| ... } ⇒ Object

Yields:

  • ([scope]) 


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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 109

def with_scope(bindings)
  scope = {}
  bindings.each do |binding|
    raise_sema_error("duplicate local #{binding.name}") if scope.key?(binding.name)

    scope[binding.name] = binding
  end

  yield([scope])
end

#with_type_resolution_scopes(scopes) ⇒ Object

Tracks the innermost value scopes during body checking so that resolve_type_ref can resolve a compile-time reflection type expression (e.g. field.type inside an inline for) by evaluating it against the local bindings in scope. Nil outside body checking.



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 66

def with_type_resolution_scopes(scopes)
  saved = @type_resolution_scopes
  @type_resolution_scopes = scopes
  yield
ensure
  @type_resolution_scopes = saved
end

#with_unsafe ⇒ Object 



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# File 'lib/milk_tea/core/semantic_analyzer/analysis_context.rb', line 6

def with_unsafe
  @unsafe_depth += 1
  yield
ensure
  @unsafe_depth -= 1
end

#zero_initializable_type?(type, operation: "zero") ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/semantic_analyzer/name_resolution.rb', line 668

def zero_initializable_type?(type, operation: "zero")
  return true if type.is_a?(Types::Primitive) && !type.void?
  return true if type.is_a?(Types::Nullable)
  return true if type.is_a?(Types::EnumBase)
  return true if span_type?(type)
  return true if string_view_type?(type)
  return true if task_type?(type)
  return true if event_type?(type)
  return true if subscription_type?(type)
  return true if type.is_a?(Types::Struct)
  return true if type.is_a?(Types::Variant)
  return true if pointer_type?(type)
  return true if type.is_a?(Types::Opaque) && !type.external
  return true if array_type?(type)
  return true if str_buffer_type?(type)
  return true if vector_type?(type)
  return true if matrix_type?(type)
  return true if quaternion_type?(type)
  return true if soa_type?(type)
  return true if simd_type?(type)
  return true if atomic_type?(type)

  raise_sema_error("#{operation} does not support type #{type}")
end