Module: MilkTea::Parse::Declarations

Included in:
MilkTea::Parser
Defined in:
lib/milk_tea/core/parser/declarations.rb

Constant Summary collapse

DECL_KIND = 
{
  var:        { method: :parse_var_decl,        reject_attrs: "var" },
  type:       { method: :parse_type_alias_decl, reject_attrs: "type" },
  union:      { method: :parse_union_decl },
  enum:       { method: :parse_enum_decl,       enum_class: AST::EnumDecl },
  flags:      { method: :parse_enum_decl,       enum_class: AST::FlagsDecl },
  opaque:     { method: :parse_opaque_decl,     reject_attrs: "opaque" },
  interface:  { method: :parse_interface_decl,  reject_attrs: "interface" },
  event:      { method: :parse_event_decl },
  attribute:  { method: :parse_attribute_decl,  reject_attrs: "attribute" },
}.freeze

Instance Method Summary collapse

Instance Method Details

#dispatch_decl_kind(kind, visibility:, attributes:) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 33

def dispatch_decl_kind(kind, visibility:, attributes:)
  info = DECL_KIND.fetch(kind)
  reject_attributes!(attributes, info[:reject_attrs]) if info[:reject_attrs]

  if info[:enum_class]
    send(info[:method], info[:enum_class], visibility:, attributes:)
  elsif info[:reject_attrs]
    send(info[:method], visibility:)
  else
    send(info[:method], visibility:, attributes:)
  end
end

#extending_target_type_param_names(type_name) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 577

def extending_target_type_param_names(type_name)
  type_name.arguments.flat_map do |argument|
    extending_target_type_param_names_from_argument(argument.value)
  end.uniq
end

#extending_target_type_param_names_from_argument(value) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 583

def extending_target_type_param_names_from_argument(value)
  case value
  when AST::TypeRef
    nested_names = value.arguments.flat_map do |argument|
      extending_target_type_param_names_from_argument(argument.value)
    end
    if value.name.parts.length == 1 && value.arguments.empty? && !value.nullable
      name = value.name.parts.first
      nested_names << name unless known_type_like_name?(name)
    end
    nested_names
  when AST::FunctionType, AST::ProcType
    value.params.flat_map { |param| extending_target_type_param_names_from_argument(param.type) } +
      extending_target_type_param_names_from_argument(value.return_type)
  else
    []
  end
end

#parse_attribute_decl(visibility: :private) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 346

def parse_attribute_decl(visibility: :private)
  line = previous.line
  consume(:lbracket, "expected '[' after attribute")
  targets = parse_comma_separated_until(:rbracket) do
    target_token = consume_path_component("expected attribute target")
    case target_token.lexeme
    when "struct"        then :struct
    when "field"         then :field
    when "callable"      then :callable
    when "const"         then :const
    when "event"         then :event
    when "enum"          then :enum
    when "flags"         then :flags
    when "union"         then :union
    when "variant"       then :variant
    else
      raise error(target_token, "unknown attribute target #{target_token.lexeme}")
    end
  end
  consume(:rbracket, "expected ']' after attribute targets")
  name_token = consume_name_allowing_keywords("expected attribute name")
  params = check(:lparen) ? parse_signature_params : []
  consume_end_of_statement
  AST::AttributeDecl.new(name: name_token.lexeme, targets:, params:, visibility:, line:, column: name_token.column)
end

#parse_block_body_safe ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 691

def parse_block_body_safe
  parse_block
rescue ParseError => e
  raise unless @recovery_errors

  @recovery_errors << e
  match(:newline)
  if match(:indent)
    begin
      parse_and_dedent_block_body || []
    rescue ParseError => e2
      @recovery_errors << e2
      []
    end
  end
end

#parse_callable_signature(allow_type_params: true, generic_error_token: nil, generic_error_message: nil, allow_body: true) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 668

def parse_callable_signature(allow_type_params: true, generic_error_token: nil, generic_error_message: nil, allow_body: true)
  type_params = parse_declaration_type_params
  if !allow_type_params && type_params.any?
    raise error(generic_error_token || previous, generic_error_message || "generic callable declarations are not allowed here")
  end

  params = nil
  return_type = nil
  body = nil

  with_type_param_names(type_params.map(&:name)) do
    params = parse_params
    return_type = match(:arrow) ? parse_type_ref : nil
    if allow_body
      body = parse_block_body_safe
    else
      consume_end_of_statement
    end
  end

  [type_params, params, return_type, body]
end

#parse_compiler_flag_directive ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 198

def parse_compiler_flag_directive
  value = consume(:string, "expected string literal after compiler_flag").literal
  consume_end_of_statement
  AST::CompilerFlagDirective.new(value:)
end

#parse_const_decl(visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 271

def parse_const_decl(visibility: :private, attributes: [])
  line = previous.line
  name = nil
  type = nil
  name_token = consume_name("expected constant name")
  name = name_token.lexeme
  if match(:arrow)
    type = parse_type_ref
    body = parse_block
    return AST::ConstDecl.new(name:, type:, value: nil, block_body: body, visibility:, attributes:, line:, column: name_token.column)
  end

  consume(:colon, "expected ':' after constant name")
  type = parse_type_ref
  consume(:equal, "expected '=' after constant type")
  value = parse_expression
  consume_end_of_statement
  AST::ConstDecl.new(name:, type:, value:, visibility:, attributes:, line:, column: name_token.column)
rescue ParseError => e
  raise unless @recovery_errors && name

  @recovery_errors << e
  synchronize_to_statement_boundary
  AST::ConstDecl.new(name:, type: type || recovery_error_expr(e), value: recovery_error_expr(e), visibility:, attributes:, line:, column: name_token.column)
end

#parse_const_or_function_decl(visibility:, attributes:) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 46

def parse_const_or_function_decl(visibility:, attributes:)
  if match(:function)
    parse_function_def(visibility:, const: true, attributes:)
  else
    parse_const_decl(visibility:, attributes:)
  end
end

#parse_declaration ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 54

def parse_declaration
  attributes = parse_attribute_applications
  visibility, visibility_token = parse_visibility

  if builtin_attribute_identifier?(peek)
    raise error(peek, "layout modifiers must use attributes like @[packed] or @[align(...)]")
  elsif match(:attribute)
    dispatch_decl_kind(:attribute, visibility:, attributes:)
  elsif match(:const)
    parse_const_or_function_decl(visibility:, attributes:)
  elsif match(:var)
    dispatch_decl_kind(:var, visibility:, attributes:)
  elsif match(:event)
    dispatch_decl_kind(:event, visibility:, attributes:)
  elsif match(:type)
    dispatch_decl_kind(:type, visibility:, attributes:)
  elsif match(:struct)
    parse_struct_decl(visibility:, attributes:)
  elsif match(:union)
    dispatch_decl_kind(:union, visibility:, attributes:)
  elsif match(:enum)
    dispatch_decl_kind(:enum, visibility:, attributes:)
  elsif match(:flags)
    dispatch_decl_kind(:flags, visibility:, attributes:)
  elsif match(:variant)
    parse_variant_decl(visibility:, attributes:)
  elsif match(:interface)
    dispatch_decl_kind(:interface, visibility:, attributes:)
  elsif match(:opaque)
    dispatch_decl_kind(:opaque, visibility:, attributes:)
  elsif match(:extending)
    reject_attributes!(attributes, "extending")
    raise error(visibility_token, "public is not allowed on extending blocks") if visibility == :public

    parse_extending_block
  elsif check(:editable) || check(:static)
    reject_attributes!(attributes, "standalone method")
    raise error(peek, "#{peek.lexeme} function is only allowed inside extending blocks")
  elsif match(:foreign)
    parse_foreign_decl(visibility:, attributes:)
  elsif match(:async)
    consume(:function, "expected function after async")
    parse_function_def(visibility:, async: true, attributes:)
  elsif match(:function)
    parse_function_def(visibility:, attributes:)
  elsif match(:external)
    raise error(visibility_token, "public is not allowed on external declarations") if visibility == :public

    parse_extern_decl(attributes:)
  elsif match(:static_assert)
    reject_attributes!(attributes, "static_assert")
    raise error(visibility_token, "public is not allowed on static_assert") if visibility == :public

    parse_static_assert
  elsif check_when_start?
    reject_attributes!(attributes, "when")
    raise error(visibility_token, "public is not allowed on when") if visibility == :public

    advance
    parse_when_decl
  else
    message = visibility == :public ? "expected exportable declaration after public" : "expected declaration"
    raise error(peek, message)
  end
end

#parse_enum_decl(node_class, visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 482

def parse_enum_decl(node_class, visibility: :private, attributes: [])
  line = previous.line
  name_token = consume_name("expected declaration name")
  name = name_token.lexeme
  consume(:colon, "expected ':' after declaration name")
  backing_type = if check(:newline) || check(:indent)
                   AST::TypeRef.new(name: AST::QualifiedName.new(parts: ["int"], type_arguments: []), arguments: [], nullable: false, lifetime: nil, line: line, column: name.length + 1)
                 else
                   parse_type_ref
                 end
  skip_newlines
  consume(:indent, "expected indented declaration body")

  members = []
  skip_newlines
  until check(:dedent) || eof?
    member_token = consume_name_allowing_keywords("expected member name")
    member_name = member_token.lexeme
    if match(:equal)
      value = parse_expression
    else
      value = nil
    end
    consume_end_of_statement
    members << AST::EnumMember.new(name: member_name, value:, line: member_token.line, column: member_token.column)
    skip_newlines
  end

  consume(:dedent, "expected end of declaration body")
  node_class.new(name:, backing_type:, members:, visibility:, attributes:, line:, column: name_token.column)
end

#parse_event_decl(visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 321

def parse_event_decl(visibility: :private, attributes: [])
  line = previous.line
  name_token = consume_name("expected event name")
  consume(:lbracket, "expected '[' after event name")
  capacity = consume(:integer, "expected positive integer capacity").literal
  consume(:rbracket, "expected ']' after event capacity")
  payload_type = nil
  if match(:lparen)
    payload_type = parse_type_ref
    consume(:rparen, "expected ')' after event payload type")
  end
  consume_end_of_statement
  AST::EventDecl.new(name: name_token.lexeme, capacity:, payload_type:, visibility:, attributes:, line:, column: name_token.column)
end

#parse_extending_block ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 564

def parse_extending_block
  line = previous.line
  type_name = parse_type_ref
  receiver_type_param_names = extending_target_type_param_names(type_name)
  methods = with_type_param_names(receiver_type_param_names) do
    parse_named_block do
      method_attributes = parse_attribute_applications
      parse_method_def(attributes: method_attributes)
    end
  end
  AST::ExtendingBlock.new(type_name:, methods:, line:, column: type_name.column)
end

#parse_extern_decl(attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 714

def parse_extern_decl(attributes: [])
  consume(:function, "expected function after external")
  parse_extern_function_decl(attributes:)
end

#parse_extern_function_decl(attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 724

def parse_extern_function_decl(attributes: [])
  line = previous.line
  name = consume_name("expected function name").lexeme
  type_params = parse_declaration_type_params
  params = nil
  variadic = false
  return_type = nil
  mapping = nil
  with_type_param_names(type_params.map(&:name)) do
    params, variadic = parse_foreign_params(allow_variadic: true)
    consume(:arrow, "expected '->' before external function return type")
    return_type = parse_type_ref
    if match(:equal)
      mapping = parse_expression
    end
  end
  consume_end_of_statement
  AST::ExternFunctionDecl.new(name:, type_params:, params:, return_type:, variadic:, attributes:, line:, mapping:)
end

#parse_foreign_decl(visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 719

def parse_foreign_decl(visibility: :private, attributes: [])
  consume(:function, "expected function after foreign")
  parse_foreign_function_decl(visibility:, attributes:)
end

#parse_foreign_function_decl(visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 744

def parse_foreign_function_decl(visibility: :private, attributes: [])
  line = previous.line
  name = consume_name("expected function name").lexeme
  type_params = parse_declaration_type_params
  params = nil
  variadic = false
  return_type = nil
  mapping = nil
  with_type_param_names(type_params.map(&:name)) do
    params, variadic = parse_foreign_params(allow_variadic: true)
    consume(:arrow, "expected '->' before foreign function return type")
    return_type = parse_type_ref
    consume(:equal, "expected '=' before foreign function mapping")
    mapping = parse_expression
  end
  consume_end_of_statement
  AST::ForeignFunctionDecl.new(name:, type_params:, params:, return_type:, variadic:, mapping:, visibility:, attributes:, line:)
end

#parse_function_def(visibility: :private, async: false, const: false, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 602

def parse_function_def(visibility: :private, async: false, const: false, attributes: [])
  line = previous.line
  name_token = consume_name("expected function name")
  name = name_token.lexeme
  type_params, params, return_type, body = parse_callable_signature
  AST::FunctionDef.new(name:, type_params:, params:, return_type:, body:, visibility:, async:, const:, attributes:, line:, column: name_token.column)
rescue ParseError => e
  raise unless @recovery_errors

  @recovery_errors << e
  AST::FunctionDef.new(name:, type_params: [], params: [], return_type: nil, body: nil, visibility:, async:, const:, attributes:, line:, column: name_token.column)
end

#parse_import ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 6

def parse_import
  line = previous.line
  path = parse_qualified_name
  local_name = path.parts.last
  local_column = previous.column
  alias_name = if match(:as)
                 alias_token = consume_name("expected import alias")
                 local_name = alias_token.lexeme
                 local_column = alias_token.column
                 alias_token.lexeme
               end
  consume_end_of_statement
  AST::Import.new(path:, alias_name:, line:, column: local_column, length: local_name.length)
end

#parse_include_directive ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 192

def parse_include_directive
  value = consume(:string, "expected string literal after include").literal
  consume_end_of_statement
  AST::IncludeDirective.new(value:)
end

#parse_interface_decl(visibility: :private) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 552

def parse_interface_decl(visibility: :private)
  line = previous.line
  name_token = consume_name("expected interface name")
  name = name_token.lexeme
  type_params = parse_declaration_type_params
  methods = parse_named_block do
    method_attributes = parse_attribute_applications
    parse_interface_method_decl(attributes: method_attributes)
  end
  AST::InterfaceDecl.new(name:, type_params:, methods:, visibility:, line:, column: name_token.column)
end

#parse_interface_method_decl(attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 630

def parse_interface_method_decl(attributes: [])
  visibility, visibility_token, async, kind, line, name_token = parse_method_like_decl_head
  raise error(visibility_token, "public is not allowed on interface methods") if visibility == :public

  name = name_token.lexeme
  _type_params, params, return_type, _body = parse_callable_signature(
    allow_type_params: false,
    generic_error_token: name_token,
    generic_error_message: "interface method #{name} cannot be generic",
    allow_body: false
  )
  AST::InterfaceMethodDecl.new(name:, params:, return_type:, kind:, async:, attributes:, line:, column: name_token.column)
end

#parse_link_directive ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 186

def parse_link_directive
  value = consume(:string, "expected string literal after link").literal
  consume_end_of_statement
  AST::LinkDirective.new(value:)
end

#parse_method_def(attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 615

def parse_method_def(attributes: [])
  visibility, _visibility_token, async, kind, line, name_token = parse_method_like_decl_head
  name = name_token.lexeme
  type_params, params, return_type, body = parse_callable_signature
  AST::MethodDef.new(name:, type_params:, params:, return_type:, body:, kind:, visibility:, async:, attributes:, line:, column: name_token.column)
rescue ParseError => e
  raise unless @recovery_errors

  @recovery_errors << e
  name = name_token&.lexeme || "unknown"
  col = name_token&.column || 1
  advance until eof? || check(:function) || check(:dedent)
  AST::MethodDef.new(name:, type_params: [], params: [], return_type: nil, body: nil, kind: kind || :plain, visibility: visibility || :private, async: async || false, attributes:, line:, column: col)
end

#parse_method_kind ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 661

def parse_method_kind
  return :editable if match(:editable)
  return :static if match(:static)

  :plain
end

#parse_method_like_decl_head ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 644

def parse_method_like_decl_head
  visibility, visibility_token = parse_visibility
  async = match(:async)
  kind = parse_method_kind
  if check(:function)
    consume(:function, "expected function declaration")
  elsif check(:identifier)
    bad_token = advance
    @recovery_errors << ParseError.new("unknown keyword '#{bad_token.lexeme}'; expected 'function' (did you mean 'editable', 'static', or 'async'?)", token: bad_token, path: @path) if @recovery_errors
  else
    raise error(peek, "expected function declaration")
  end
  line = previous.line
  name_token = consume_name("expected function name")
  [visibility, visibility_token, async, kind, line, name_token]
end

#parse_opaque_decl(visibility: :private) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 539

def parse_opaque_decl(visibility: :private)
  line = previous.line
  name_token = consume_name("expected opaque type name")
  name = name_token.lexeme
  implements = parse_implements_clause
  c_name = nil
  if match(:equal)
    c_name = consume(:cstring, "expected C string literal after '='").literal
  end
  consume_end_of_statement
  AST::OpaqueDecl.new(name:, implements:, c_name:, visibility:, line:, column: name_token.column)
end

#parse_optional_explicit_c_name ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 476

def parse_optional_explicit_c_name
  return nil unless match(:equal)

  consume(:cstring, "expected C string literal after '='").literal
end

#parse_raw_module_body(errors: nil) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 120

def parse_raw_module_body(errors: nil)
  imports = []
  directives = []
  declarations = []

  while match(:import)
    if errors
      begin
        imports << parse_import
      rescue ParseError => e
        errors << e
        synchronize_to_top_level_boundary
      end
    else
      imports << parse_import
    end
    skip_newlines
  end

  while raw_module_directive_start?
    if errors
      begin
        directives << parse_raw_module_directive
      rescue ParseError => e
        errors << e
        synchronize_to_top_level_boundary
      end
    else
      directives << parse_raw_module_directive
    end
    skip_newlines
  end

  until eof?
    if errors
      begin
        declarations << parse_raw_module_declaration
      rescue ParseError => e
        errors << e
        synchronize_to_top_level_boundary
      end
    else
      declarations << parse_raw_module_declaration
    end
    skip_newlines
  end

  [imports, directives, declarations]
end

#parse_raw_module_declaration ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 204

def parse_raw_module_declaration
  attributes = parse_attribute_applications

  if match(:public)
    reject_attributes!(attributes)
    raise error(previous, "public is not allowed in external files")
  elsif builtin_attribute_identifier?(peek)
    raise error(peek, "layout modifiers must use attributes like @[packed] or @[align(...)]")
  elsif match(:attribute)
    reject_attributes!(attributes)
    raise error(previous, "attribute is not allowed in external files")
  elsif match(:const)
    reject_attributes!(attributes)
    if match(:function)
      parse_function_def(visibility:, const: true, attributes:)
    else
      parse_const_decl(visibility: nil)
    end
  elsif match(:event)
    reject_attributes!(attributes)
    raise error(previous, "event is not allowed in external files")
  elsif match(:type)
    reject_attributes!(attributes)
    parse_type_alias_decl(visibility: nil)
  elsif match(:struct)
    parse_struct_decl(visibility: nil, attributes:)
  elsif match(:union)
    reject_attributes!(attributes)
    parse_union_decl(visibility: nil)
  elsif match(:enum)
    reject_attributes!(attributes)
    parse_enum_decl(AST::EnumDecl, visibility: nil)
  elsif match(:flags)
    reject_attributes!(attributes)
    parse_enum_decl(AST::FlagsDecl, visibility: nil)
  elsif match(:opaque)
    reject_attributes!(attributes)
    parse_opaque_decl(visibility: nil)
  elsif match(:external)
    reject_attributes!(attributes)
    parse_extern_decl(attributes:)
  elsif check_when_start?
    reject_attributes!(attributes)
    advance
    parse_when_stmt
  else
    raise error(peek, raw_module_declaration_error_message(peek))
  end
end

#parse_raw_module_directive ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 174

def parse_raw_module_directive
  if match(:link)
    parse_link_directive
  elsif match(:include)
    parse_include_directive
  elsif match(:compiler_flag)
    parse_compiler_flag_directive
  else
    raise error(peek, "expected external directive")
  end
end

#parse_struct_decl(packed: false, alignment: nil, visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 372

def parse_struct_decl(packed: false, alignment: nil, visibility: :private, attributes: [])
  line = previous.line
  name_token = consume_name("expected struct name")
  name = name_token.lexeme
  lifetime_params, type_params = parse_struct_decl_params
  implements = parse_implements_clause
  c_name = parse_optional_explicit_c_name
  packed, alignment = parse_struct_layout_attributes(attributes) if attributes.any?
  members = parse_named_block do
    parse_struct_member
  end
  fields = members.filter_map { |kind, member| member if kind == :field }
  events = members.filter_map { |kind, member| member if kind == :event }
  nested_types = members.filter_map { |kind, member| member if kind == :nested_type }
  AST::StructDecl.new(name:, type_params:, implements:, c_name:, fields:, events:, nested_types:, attributes:, packed:, alignment:, visibility:, lifetime_params:, line:, column: name_token.column)
end

#parse_struct_decl_params ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 389

def parse_struct_decl_params
  return [[], []] unless match(:lbracket)

  lifetime_params = []
  type_params = []

  loop do
    break if check(:rbracket)

    if match(:at)
      name_token = consume_name_allowing_keywords("expected lifetime name after @")
      lifetime_params << "@#{name_token.lexeme}"
    else
      name_token = consume_name_allowing_keywords("expected type parameter name")
      if match(:colon)
        value_type = parse_type_ref
        type_params << AST::ValueTypeParam.new(
          name: name_token.lexeme,
          type: value_type,
          line: name_token.line,
          column: name_token.column,
          length: name_token.lexeme.length,
        )
      else
        constraints = parse_type_param_constraints
        type_params << AST::TypeParam.new(
          name: name_token.lexeme,
          constraints:,
          line: name_token.line,
          column: name_token.column,
          length: name_token.lexeme.length,
        )
      end
    end

    break unless match(:comma)
    next if check(:rbracket)
  end

  consume(:rbracket, "expected ']' after struct parameters")
  [lifetime_params, type_params]
end

#parse_struct_member ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 432

def parse_struct_member
  field_attributes = parse_attribute_applications
  visibility, visibility_token = parse_visibility

  if match(:event)
    return [:event, parse_event_decl(visibility:, attributes: field_attributes)]
  end

  if match(:struct)
    return [:nested_type, parse_struct_decl(visibility:, attributes: field_attributes)]
  end

  raise error(visibility_token, "public is only allowed on struct events") if visibility == :public

  field_token = consume_name_allowing_keywords("expected field name")
  field_name = field_token.lexeme
  consume(:colon, "expected ':' after field name")
  field_type = parse_type_ref
  consume_end_of_statement
  [:field, AST::Field.new(name: field_name, type: field_type, attributes: field_attributes, line: field_token.line, column: field_token.column)]
rescue ParseError => e
  raise unless @recovery_errors

  @recovery_errors << e
  synchronize_to_statement_boundary
  field_name_error = (field_name if defined?(field_name)) || "error"
  [:field, AST::Field.new(name: field_name_error, type: recovery_error_expr(e), attributes: field_attributes, line: e.token&.line || 1, column: e.token&.column || 1)]
end

#parse_type_alias_decl(visibility: :private) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 336

def parse_type_alias_decl(visibility: :private)
  line = previous.line
  name_token = consume_name("expected type alias name")
  name = name_token.lexeme
  consume(:equal, "expected '=' after type alias name")
  target = parse_type_ref
  consume_end_of_statement
  AST::TypeAliasDecl.new(name:, target:, visibility:, line:, column: name_token.column)
end

#parse_union_decl(visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 461

def parse_union_decl(visibility: :private, attributes: [])
  line = previous.line
  name_token = consume_name("expected union name")
  name = name_token.lexeme
  c_name = parse_optional_explicit_c_name
  fields = parse_named_block do
                 field_name = consume_name_allowing_keywords("expected field name").lexeme
    consume(:colon, "expected ':' after field name")
    field_type = parse_type_ref
    consume_end_of_statement
    AST::Field.new(name: field_name, type: field_type)
  end
  AST::UnionDecl.new(name:, c_name:, fields:, visibility:, attributes:, line:, column: name_token.column)
end

#parse_var_decl(visibility: :private) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 297

def parse_var_decl(visibility: :private)
  line = previous.line
  name = nil
  var_type = nil
  name_token = consume_name("expected variable name")
  name = name_token.lexeme
  var_type = match(:colon) ? parse_type_ref : nil
  value = if match(:equal)
            parse_expression
          else
            raise error(name_token, "module variable without initializer requires a type") unless var_type

            nil
          end
  consume_end_of_statement
  AST::VarDecl.new(name:, type: var_type, value:, visibility:, line:, column: name_token.column)
rescue ParseError => e
  raise unless @recovery_errors && name

  @recovery_errors << e
  synchronize_to_statement_boundary
  AST::VarDecl.new(name:, type: var_type || recovery_error_expr(e), value: recovery_error_expr(e), visibility:, line:, column: name_token.column)
end

#parse_variant_decl(visibility: :private, attributes: []) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 514

def parse_variant_decl(visibility: :private, attributes: [])
  line = previous.line
  name_token = consume_name("expected variant name")
  name = name_token.lexeme
  type_params = parse_declaration_type_params
  arms = parse_named_block do
    arm_name = consume_name_allowing_keywords("expected variant arm name").lexeme
    fields = if match(:lparen)
               parsed = parse_comma_separated_until(:rparen) do
    field_name = consume_name_allowing_keywords("expected field name").lexeme
                 consume(:colon, "expected ':' after field name")
                 field_type = parse_type_ref
                 AST::Field.new(name: field_name, type: field_type)
               end
               consume(:rparen, "expected ')' after variant arm fields")
               parsed
             else
               []
             end
    consume_end_of_statement
    AST::VariantArm.new(name: arm_name, fields:)
  end
  AST::VariantDecl.new(name:, type_params:, arms:, visibility:, attributes:, line:, column: name_token.column)
end

#parse_visibility ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 708

def parse_visibility
  return [:public, previous] if match(:public)

  [:private, nil]
end

#raw_module_declaration_error_message(token) ⇒ Object 



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# File 'lib/milk_tea/core/parser/declarations.rb', line 254

def raw_module_declaration_error_message(token)
  case token.type
  when :import
    "imports must appear before external directives and declarations"
  when :link, :include, :compiler_flag
    "#{token.lexeme} directives must appear before external declarations"
  when :attribute, :event, :var, :variant, :interface, :extending, :foreign, :function, :static_assert
    "#{token.lexeme} is not allowed in external files"
  when :async
    "async function is not allowed in external files"
  when :module
    "module headers are not allowed in external files"
  else
    "expected external declaration"
  end
end

#raw_module_directive_start? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/parser/declarations.rb', line 170

def raw_module_directive_start?
  check(:link) || check(:include) || check(:compiler_flag)
end