Class: MilkTea::PrettyPrinter::ASTFormatter

Inherits:
BaseFormatter show all
Defined in:
lib/milk_tea/core/pretty_printer/ast_formatter.rb

Constant Summary collapse

IF_EXPRESSION_PRECEDENCE = 
5
POSTFIX_PRECEDENCE = 
90
UNARY_PRECEDENCE = 
80
IS_PRECEDENCE = 
25
BLOCK_DECLARATION_TYPES = 
[
  AST::FunctionDef, AST::ForeignFunctionDecl, AST::InterfaceDecl, AST::ExtendingBlock,
  AST::StructDecl, AST::UnionDecl, AST::EnumDecl, AST::FlagsDecl, AST::VariantDecl,
].freeze

Constants inherited from BaseFormatter

BaseFormatter::INDENT

Instance Method Summary collapse

Methods inherited from BaseFormatter

#binding_name, #blank_line, #capture_lines, #finish, #initialize, #line, #precedence, #with_indent, #wrap

Constructor Details

This class inherits a constructor from MilkTea::PrettyPrinter::BaseFormatter

Instance Method Details

#attach_inline_comment(line_no, header_idx) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 39

def attach_inline_comment(line_no, header_idx)
  return unless line_no && header_idx < @lines.length
  return unless @comment_map.key?(line_no)

  comments = @comment_map.delete(line_no)
  return if comments.empty?

  @lines[header_idx] = "#{@lines[header_idx]}  #{comments.first}"
end

#block_declaration?(declaration) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 108

def block_declaration?(declaration)
  BLOCK_DECLARATION_TYPES.any? { |t| declaration.is_a?(t) }
end

#boolean_literal?(node, value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 894

def boolean_literal?(node, value)
  node.is_a?(AST::BooleanLiteral) && node.value == value
end

#build_comment_map(trivia) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 17

def build_comment_map(trivia)
  @blank_line_set = {}
  map = {}
  trivia.each do |t|
    case t.kind
    when :comment
      (map[t.line] ||= []) << t.text.strip
    when :blank_line
      @blank_line_set[t.line] = true
    end
  end
  map
end

#declaration_node?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 583

def declaration_node?(node)
  case node
  when AST::FunctionDef, AST::StructDecl, AST::UnionDecl, AST::EnumDecl,
       AST::FlagsDecl, AST::VariantDecl, AST::OpaqueDecl, AST::InterfaceDecl,
       AST::ExtendingBlock, AST::TypeAliasDecl, AST::AttributeDecl, AST::EventDecl,
       AST::ExternFunctionDecl, AST::ForeignFunctionDecl, AST::VarDecl, AST::MethodDef
    true
  else
    false
  end
end

#declaration_separator_required?(declaration, next_decl) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 112

def declaration_separator_required?(declaration, next_decl)
  if @current_module_kind == :raw_module
    return raw_module_separator_required?(declaration, next_decl)
  end

  block_declaration?(declaration) || block_declaration?(next_decl)
end

#emit_attribute_applications(attributes) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 389

def emit_attribute_applications(attributes)
  attributes.each do |attribute|
    line(render_attribute_application(attribute))
  end
end

#emit_block_item(node) ⇒ Object

A when branch body is statements at function level but declarations at module level; dispatch on the node kind.



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 575

def emit_block_item(node)
  if declaration_node?(node)
    emit_declaration(node)
  else
    emit_statement(node)
  end
end

#emit_const(declaration) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 604

def emit_const(declaration)
  emit_attribute_applications(declaration.attributes)
  header = "#{visibility_prefix(declaration)}const #{declaration.name}"
  if declaration.block_body
    line("#{header} -> #{render_type(declaration.type)}:")
    with_indent do
      declaration.block_body.each { |nested| emit_statement(nested) }
    end
  else
    header += ": #{render_type(declaration.type)}" if declaration.type
    line("#{header} = #{render_expression(declaration.value)}")
  end
end

#emit_declaration(declaration) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 146

def emit_declaration(declaration)
  decl_line = declaration.line
  flush_leading_comments_before(decl_line)
  header_idx = @lines.length

  case declaration
  when AST::ConstDecl
    emit_const(declaration)
  when AST::VarDecl
    header = "#{visibility_prefix(declaration)}var #{declaration.name}"
    header += ": #{render_type(declaration.type)}" if declaration.type
    if declaration.value
      line("#{header} = #{render_expression(declaration.value)}")
    else
      line(header)
    end
  when AST::EventDecl
    emit_attribute_applications(declaration.attributes)
    line(render_event_declaration(declaration))
  when AST::TypeAliasDecl
    line("#{visibility_prefix(declaration)}type #{declaration.name} = #{render_type(declaration.target)}")
  when AST::AttributeDecl
    text = "#{visibility_prefix(declaration)}attribute[#{declaration.targets.join(', ')}] #{declaration.name}"
    text += "(#{declaration.params.map { |param| render_param(param) }.join(', ')})" unless declaration.params.empty?
    line(text)
  when AST::StaticAssert
    line("static_assert(#{render_expression(declaration.condition)}, #{render_expression(declaration.message)})")
  when AST::StructDecl
    emit_attribute_applications(declaration.attributes)
    header_idx = @lines.length
    header = +""
    header << visibility_prefix(declaration)
    header << "struct #{declaration.name}#{render_struct_params(declaration.lifetime_params, declaration.type_params)}"
    header << render_implements_clause(declaration.implements)
    header << " = c#{declaration.c_name.inspect}" if declaration.c_name
    header << ":"
    line(header)
    with_indent do
      declaration.fields.each do |field|
        emit_attribute_applications(field.attributes)
        line("#{field.name}: #{render_type(field.type)}")
      end
      declaration.nested_types.each do |nested|
        emit_declaration(nested)
      end
      declaration.events.each do |event|
        line(render_event_declaration(event))
      end
    end
  when AST::UnionDecl
    emit_attribute_applications(declaration.attributes)
    header = "#{visibility_prefix(declaration)}union #{declaration.name}"
    header += " = c#{declaration.c_name.inspect}" if declaration.c_name
    line("#{header}:")
    with_indent do
      declaration.fields.each do |field|
        line("#{field.name}: #{render_type(field.type)}")
      end
    end
  when AST::EnumDecl
    emit_attribute_applications(declaration.attributes)
    emit_enum_like("enum", declaration.name, declaration.backing_type, declaration.members, declaration.visibility)
  when AST::FlagsDecl
    emit_attribute_applications(declaration.attributes)
    emit_enum_like("flags", declaration.name, declaration.backing_type, declaration.members, declaration.visibility)
  when AST::VariantDecl
    emit_attribute_applications(declaration.attributes)
    header = "#{visibility_prefix(declaration)}variant #{declaration.name}"
    header += render_type_params(declaration.type_params) if declaration.type_params.any?
    line("#{header}:")
    with_indent do
      declaration.arms.each do |arm|
        arm_text = +"#{arm.name}"
        if arm.fields.any?
          field_strs = arm.fields.map { |f| "#{f.name}: #{render_type(f.type)}" }
          arm_text += "(#{field_strs.join(', ')})"
        end
        line(arm_text)
      end
    end
  when AST::OpaqueDecl
    text = "#{visibility_prefix(declaration)}opaque #{declaration.name}"
    text += render_implements_clause(declaration.implements)
    text += " = c#{declaration.c_name.inspect}" if declaration.c_name
    line(text)
  when AST::InterfaceDecl
    header = "#{visibility_prefix(declaration)}interface #{declaration.name}"
    header += render_type_params(declaration.type_params) if declaration.type_params.any?
    line("#{header}:")
    with_indent do
      declaration.methods.each do |method|
        emit_attribute_applications(method.attributes)
        line(render_interface_method_signature(method))
      end
    end
  when AST::ExtendingBlock
    line("extending #{render_type(declaration.type_name)}:")
    with_indent do
      declaration.methods.each_with_index do |method, index|
        emit_function(method)
        blank_line if index < (declaration.methods.length - 1)
      end
    end
  when AST::FunctionDef
    emit_function(declaration)
  when AST::ExternFunctionDecl
    emit_attribute_applications(declaration.attributes)
    header_idx = @lines.length
    line = "#{render_function_signature(declaration, prefix: 'external ')}"
    line += " = #{render_expression(declaration.mapping)}" if declaration.mapping
    line(line)
  when AST::ForeignFunctionDecl
    emit_attribute_applications(declaration.attributes)
    header_idx = @lines.length
    line("#{render_function_signature(declaration)} = #{render_expression(declaration.mapping)}")
  when AST::WhenStmt
    emit_when(declaration)
  else
    raise ArgumentError, "unsupported AST declaration #{declaration.class.name}"
  end

  attach_inline_comment(decl_line, header_idx)
end

#emit_enum_like(kind, name, backing_type, members, visibility) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 270

def emit_enum_like(kind, name, backing_type, members, visibility)
  header = "#{visibility_prefix(visibility)}#{kind} #{name}"
  header += ": #{render_type(backing_type)}" if backing_type
  line(header)
  with_indent do
    members.each do |member|
      text = member.name
      text += " = #{render_expression(member.value)}" if member.value
      line(text)
    end
  end
end

#emit_function(function) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 289

def emit_function(function)
  emit_attribute_applications(function.attributes)
  line("#{render_function_signature(function)}:")
  with_indent do
    function.body.each do |statement|
      emit_statement(statement)
    end
  end
end

#emit_if(statement) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 672

def emit_if(statement)
  first_branch, *rest = statement.branches
  prefix = statement.inline ? "inline if" : "if"
  line("#{prefix} #{render_expression(first_branch.condition)}:")
  with_indent do
    first_branch.body.each { |nested| emit_statement(nested) }
  end

  rest.each do |branch|
    line("else if #{render_expression(branch.condition)}:")
    with_indent do
      branch.body.each { |nested| emit_statement(nested) }
    end
  end

  else_body = statement.else_body || []
  return if else_body.empty?

  line("else:")
  with_indent do
    else_body.each { |nested| emit_statement(nested) }
  end
end

#emit_module_body(source_file) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 61

def emit_module_body(source_file)
  wrote_section = false

  unless source_file.imports.empty?
    source_file.imports.each do |import|
      flush_leading_comments_before(import.line)
      line(render_import(import))
      attach_inline_comment(import.line, @lines.length - 1)
    end
    wrote_section = true
  end

  unless source_file.directives.empty?
    blank_line if wrote_section
    source_file.directives.each { |directive| line(render_directive(directive)) }
    wrote_section = true
  end

  if source_file.declarations.empty?
    flush_remaining_comments
    return
  end

  blank_line if wrote_section
  source_file.declarations.each_with_index do |declaration, index|
    emit_declaration(declaration)
    next_decl = source_file.declarations[index + 1]
    if next_decl && declaration_separator_required?(declaration, next_decl)
      blank_line
    end
  end

  flush_remaining_comments
end

#emit_source_file(source_file) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 49

def emit_source_file(source_file)
  @current_module_kind = source_file.module_kind
  if source_file.module_kind == :raw_module
    flush_leading_comments_before(source_file.line) if source_file.line
    line("external")
    attach_inline_comment(source_file.line, @lines.length - 1)
    blank_line unless source_file.imports.empty? && source_file.directives.empty? && source_file.declarations.empty?
  end

  emit_module_body(source_file)
end

#emit_statement(statement) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 445

def emit_statement(statement)
  stmt_line = statement.line
  flush_leading_comments_before(stmt_line)
  header_idx = @lines.length

  case statement
  when AST::LocalDecl
    if statement.destructure_bindings
      text = "#{statement.kind} #{render_destructure_target(statement)}"
    else
      text = "#{statement.kind} #{statement.name}"
      text += ": #{render_type(statement.type)}" if statement.type
    end
    text += " = #{render_expression(statement.value)}" if statement.value
    if statement.else_body
      else_header = statement.else_binding ? "else as #{statement.else_binding.name}:" : "else:"
      line("#{text} #{else_header}")
      with_indent do
        statement.else_body.each { |nested| emit_statement(nested) }
      end
    else
      line(text)
    end
  when AST::Assignment
    line("#{render_expression(statement.target)} #{statement.operator} #{render_expression(statement.value)}")
  when AST::IfStmt
    emit_if(statement)
  when AST::MatchStmt
    prefix = statement.inline ? "inline match" : "match"
    line("#{prefix} #{render_expression(statement.expression)}:")
    with_indent do
      statement.arms.each do |arm|
        binding = arm.binding_name ? " as #{arm.binding_name}" : ""
        line("#{render_expression(arm.pattern)}#{binding}:")
        with_indent do
          arm.body.each { |nested| emit_statement(nested) }
        end
      end
    end
  when AST::UnsafeStmt
    if (inline = render_inline_unsafe(statement))
      line(inline)
    else
      line("unsafe:")
      with_indent do
        statement.body.each { |nested| emit_statement(nested) }
      end
    end
  when AST::StaticAssert
    line("static_assert(#{render_expression(statement.condition)}, #{render_expression(statement.message)})")
  when AST::EmitStmt
    before = @lines.length
    emit_declaration(statement.declaration)
    @lines[before] = @lines[before].sub(/\A(\s*)/, "\\1emit ") if @lines[before]
  when AST::ForStmt
    prefix = +""
    prefix << "parallel " if statement.threaded
    prefix << "inline " if statement.inline
    bindings = statement.bindings.map(&:name).join(", ")
    iterables = statement.iterables.map { |iterable| render_expression(iterable) }.join(", ")
    line("#{prefix}for #{bindings} in #{iterables}:")
    with_indent do
      statement.body.each { |nested| emit_statement(nested) }
    end
  when AST::WhileStmt
    prefix = statement.inline ? "inline while" : "while"
    line("#{prefix} #{render_expression(statement.condition)}:")
    with_indent do
      statement.body.each { |nested| emit_statement(nested) }
    end
  when AST::PassStmt
    line("pass")
  when AST::BreakStmt
    line("break")
  when AST::ContinueStmt
    line("continue")
  when AST::ReturnStmt
    line(statement.value ? "return #{render_expression(statement.value)}" : "return")
  when AST::DeferStmt
    if statement.body
      line("defer:")
      with_indent do
        statement.body.each { |nested| emit_statement(nested) }
      end
    else
      line("defer #{render_expression(statement.expression)}")
    end
  when AST::ExpressionStmt
    line(render_expression(statement.expression))
  when AST::ParallelBlockStmt
    line("parallel:")
    with_indent do
      statement.bodies.each do |body|
        body.each { |nested| emit_statement(nested) }
      end
    end
  when AST::GatherStmt
    line("gather #{statement.handles.map { |handle| render_expression(handle) }.join(', ')}")
  when AST::WhenStmt
    emit_when(statement)
  when AST::ConstDecl
    emit_const(statement)
  else
    raise ArgumentError, "unsupported AST statement #{statement.class.name}"
  end

  attach_inline_comment(stmt_line, header_idx)
end

#emit_when(statement) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 554

def emit_when(statement)
  line("when #{render_expression(statement.discriminant)}:")
  with_indent do
    statement.branches.each do |branch|
      binding = branch.binding_name ? " as #{branch.binding_name}" : ""
      line("#{render_expression(branch.pattern)}#{binding}:")
      with_indent do
        branch.body.each { |nested| emit_block_item(nested) }
      end
    end
    if statement.else_body
      line("else:")
      with_indent do
        statement.else_body.each { |nested| emit_block_item(nested) }
      end
    end
  end
end

#escape_format_text(value) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 863

def escape_format_text(value)
  value.gsub(/[\\"\n\r\t\0]/) do |char|
    case char
    when "\\" then "\\\\"
    when '"' then '\\"'
    when "\n" then "\\n"
    when "\r" then "\\r"
    when "\t" then "\\t"
    when "\0" then "\\0"
    end
  end
end

#flush_leading_comments_before(stmt_line) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 31

def flush_leading_comments_before(stmt_line)
  return unless stmt_line

  @comment_map.keys.select { |line| line < stmt_line }.sort.each do |line_no|
    @comment_map.delete(line_no)&.each { |text| line(text) }
  end
end

#flush_remaining_comments ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 96

def flush_remaining_comments
  sorted = @comment_map.keys.sort
  sorted.each do |l|
    @comment_map.delete(l)&.each { |text| line(text) }
  end
end

#format(node, trivia: []) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 11

def format(node, trivia: [])
  @comment_map = build_comment_map(trivia)
  emit_source_file(node)
  finish
end

#postfix_expression?(expression) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 908

def postfix_expression?(expression)
  expression.is_a?(AST::Identifier) || expression.is_a?(AST::MemberAccess) || expression.is_a?(AST::IndexAccess) ||
    expression.is_a?(AST::Specialization) || expression.is_a?(AST::Call) ||
    (expression.is_a?(AST::UnaryOp) && expression.operator == "?")
end

#raw_module_block_declaration?(declaration) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 126

def raw_module_block_declaration?(declaration)
  declaration.is_a?(AST::StructDecl) ||
    declaration.is_a?(AST::UnionDecl) ||
    declaration.is_a?(AST::EnumDecl) ||
    declaration.is_a?(AST::FlagsDecl)
end

#raw_module_declaration_group(declaration) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 133

def raw_module_declaration_group(declaration)
  case declaration
  when AST::OpaqueDecl, AST::TypeAliasDecl
    :types
  when AST::ConstDecl
    :values
  when AST::ExternFunctionDecl
    :functions
  else
    declaration.class.name
  end
end

#raw_module_separator_required?(declaration, next_decl) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 120

def raw_module_separator_required?(declaration, next_decl)
  return true if raw_module_block_declaration?(declaration) || raw_module_block_declaration?(next_decl)

  raw_module_declaration_group(declaration) != raw_module_declaration_group(next_decl)
end

#render_argument(argument) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 834

def render_argument(argument)
  return render_expression(argument.value) unless argument.name

  "#{argument.name} = #{render_expression(argument.value)}"
end

#render_attribute_application(attribute) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 395

def render_attribute_application(attribute)
  text = +"@[#{attribute.name}"
  unless attribute.arguments.empty?
    rendered_arguments = attribute.arguments.map do |argument|
      if argument.name
        "#{argument.name} = #{render_expression(argument.value)}"
      else
        render_expression(argument.value)
      end
    end
    text << "(#{rendered_arguments.join(', ')})"
  end
  text << "]"
  text
end

#render_destructure_target(statement) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 595

def render_destructure_target(statement)
  names = statement.destructure_bindings.join(", ")
  type_name = statement.destructure_type_name
  return "(#{names})" unless type_name

  prefix = type_name.is_a?(Array) ? type_name.join(".") : type_name
  "#{prefix}(#{names})"
end

#render_directive(directive) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 432

def render_directive(directive)
  case directive
  when AST::LinkDirective
    "link #{directive.value.inspect}"
  when AST::IncludeDirective
    "include #{directive.value.inspect}"
  when AST::CompilerFlagDirective
    "compiler_flag #{directive.value.inspect}"
  else
    raise ArgumentError, "unsupported AST directive #{directive.class.name}"
  end
end

#render_event_declaration(declaration) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 283

def render_event_declaration(declaration)
  text = +"#{visibility_prefix(declaration)}event #{declaration.name}[#{declaration.capacity}]"
  text << "(#{render_type(declaration.payload_type)})" if declaration.payload_type
  text
end

#render_expression(expression, parent_precedence = 0) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 746

def render_expression(expression, parent_precedence = 0)
  case expression
  when AST::Identifier
    expression.name
  when AST::MemberAccess
    wrap("#{render_postfix(expression.receiver)}.#{expression.member}", parent_precedence, POSTFIX_PRECEDENCE)
  when AST::IndexAccess
    wrap("#{render_postfix(expression.receiver)}[#{render_expression(expression.index)}]", parent_precedence, POSTFIX_PRECEDENCE)
  when AST::Specialization
    wrap("#{render_postfix(expression.callee)}[#{expression.arguments.map { |argument| render_type_argument(argument.value) }.join(', ')}]", parent_precedence, POSTFIX_PRECEDENCE)
  when AST::Call
    wrap("#{render_postfix(expression.callee)}(#{expression.arguments.map { |argument| render_argument(argument) }.join(', ')})", parent_precedence, POSTFIX_PRECEDENCE)
  when AST::PrefixCast
    wrap("#{render_type(expression.target_type)}<-#{render_expression(expression.expression, UNARY_PRECEDENCE)}", parent_precedence, UNARY_PRECEDENCE)
  when AST::UnaryOp
    if expression.operator == "?"
      return wrap("#{render_postfix(expression.operand)}?", parent_precedence, POSTFIX_PRECEDENCE)
    end

    operand = render_expression(expression.operand, UNARY_PRECEDENCE)
    text = %w[not out in inout].include?(expression.operator) ? "#{expression.operator} #{operand}" : "#{expression.operator}#{operand}"
    wrap(text, parent_precedence, UNARY_PRECEDENCE)
  when AST::BinaryOp
    current_precedence = precedence(expression.operator)
    left = render_expression(expression.left, current_precedence)
    right = render_expression(expression.right, current_precedence + 1)
    wrap("#{left} #{expression.operator} #{right}", parent_precedence, current_precedence)
  when AST::RangeExpr
    left = render_expression(expression.start_expr)
    right = render_expression(expression.end_expr)
    "#{left}..#{right}"
  when AST::ExpressionList
    "(#{expression.elements.map { |element| render_list_element(element) }.join(', ')})"
  when AST::IfExpr
    condition = render_expression(expression.condition, IF_EXPRESSION_PRECEDENCE)
    then_expression = render_expression(expression.then_expression, IF_EXPRESSION_PRECEDENCE)
    else_expression = render_expression(expression.else_expression, IF_EXPRESSION_PRECEDENCE)
    wrap("if #{condition}: #{then_expression} else: #{else_expression}", parent_precedence, IF_EXPRESSION_PRECEDENCE)
  when AST::MatchExpr
    sugared = render_is_expression(expression, parent_precedence)
    return sugared if sugared

    rendered_expression = render_expression(expression.expression, IF_EXPRESSION_PRECEDENCE)
    arm_indent = INDENT * (@indent + 1)
    rendered_arms = expression.arms.map do |arm|
      binding = arm.binding_name ? " as #{arm.binding_name}" : ""
      "#{render_expression(arm.pattern)}#{binding}: #{render_expression(arm.value, IF_EXPRESSION_PRECEDENCE)}"
    end.join("\n#{arm_indent}")
    "match #{rendered_expression}:\n#{arm_indent}#{rendered_arms}"
  when AST::UnsafeExpr
    inner = render_expression(expression.expression, IF_EXPRESSION_PRECEDENCE)
    wrap("unsafe: #{inner}", parent_precedence, IF_EXPRESSION_PRECEDENCE)
  when AST::ProcExpr
    params = expression.params.map { |param| render_param(param) }.join(', ')
    if expression.body.length == 1 && expression.body.first.is_a?(AST::ReturnStmt) && expression.body.first.value
      body_expression = render_expression(expression.body.first.value, IF_EXPRESSION_PRECEDENCE)
      wrap("proc(#{params}) -> #{render_type(expression.return_type)}: #{body_expression}", parent_precedence, IF_EXPRESSION_PRECEDENCE)
    else
      body_lines = capture_lines do
        with_indent do
          expression.body.each { |statement| emit_statement(statement) }
        end
      end
      "proc(#{params}) -> #{render_type(expression.return_type)}:\n#{body_lines.join("\n")}"
    end
  when AST::AwaitExpr
    wrap("await #{render_expression(expression.expression, UNARY_PRECEDENCE)}", parent_precedence, UNARY_PRECEDENCE)
  when AST::SizeofExpr
    "size_of(#{render_type(expression.type)})"
  when AST::AlignofExpr
    "align_of(#{render_type(expression.type)})"
  when AST::OffsetofExpr
    "offset_of(#{render_type(expression.type)}, #{expression.field})"
  when AST::IntegerLiteral, AST::FloatLiteral, AST::StringLiteral, AST::CharLiteral
    expression.lexeme
  when AST::FormatString
    "f\"#{expression.parts.map { |part| render_format_string_part(part) }.join}\""
  when AST::BooleanLiteral
    expression.value ? "true" : "false"
  when AST::NullLiteral
    expression.type ? "null[#{render_type(expression.type)}]" : "null"
  when AST::DetachExpr
    wrap("detach #{render_expression(expression.body.first.expression, UNARY_PRECEDENCE)}", parent_precedence, UNARY_PRECEDENCE)
  else
    raise ArgumentError, "unsupported AST expression #{expression.class.name}"
  end
end

#render_format_string_part(part) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 846

def render_format_string_part(part)
  case part
  when AST::FormatTextPart
    escape_format_text(part.value)
  when AST::FormatExprPart
    spec = case part.format_spec&.fetch(:kind)
    when :precision then ":.#{part.format_spec[:value]}"
    when :hex then part.format_spec[:uppercase] ? ":X" : ":x"
    when :oct then part.format_spec[:uppercase] ? ":O" : ":o"
    when :bin then part.format_spec[:uppercase] ? ":B" : ":b"
    end
    "\#{#{render_expression(part.expression)}#{spec}}"
  else
    raise ArgumentError, "unsupported format string part #{part.class.name}"
  end
end

#render_function_signature(function, prefix: "") ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 299

def render_function_signature(function, prefix: "")
  signature_prefix = if function.is_a?(AST::MethodDef)
    case function.kind
    when :editable
      "editable function "
    when :static
      "static function "
    else
      "function "
    end
  elsif function.is_a?(AST::ForeignFunctionDecl)
    "foreign function "
  else
    "function "
  end
  async_prefix = function.respond_to?(:async) && function.async ? "async " : ""
  text = +"#{prefix}#{visibility_prefix(function)}#{async_prefix}#{signature_prefix}#{function.name}#{render_type_params(function.type_params)}(#{render_signature_params(function)})"
  text << " -> #{render_type(function.return_type)}" if function.return_type
  text
end

#render_implements_clause(implements) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 383

def render_implements_clause(implements)
  return "" if implements.empty?

  " implements #{implements.map(&:to_s).join(', ')}"
end

#render_import(import) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 426

def render_import(import)
  text = "import #{import.path}"
  text += " as #{import.alias_name}" if import.alias_name
  text
end

#render_inline_statement(statement) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 631

def render_inline_statement(statement)
  case statement
  when AST::LocalDecl
    return nil if statement.else_body

    text = +"#{statement.kind} #{statement.name}"
    text << ": #{render_type(statement.type)}" if statement.type
    text << " = #{render_expression(statement.value)}" if statement.value
    text
  when AST::Assignment
    "#{render_expression(statement.target)} #{statement.operator} #{render_expression(statement.value)}"
  when AST::StaticAssert
    "static_assert(#{render_expression(statement.condition)}, #{render_expression(statement.message)})"
  when AST::PassStmt
    "pass"
  when AST::BreakStmt
    "break"
  when AST::ContinueStmt
    "continue"
  when AST::ReturnStmt
    statement.value ? "return #{render_expression(statement.value)}" : "return"
  when AST::DeferStmt
    return nil if statement.body

    "defer #{render_expression(statement.expression)}"
  when AST::ExpressionStmt
    render_expression(statement.expression)
  else
    nil
  end
end

#render_inline_unsafe(statement) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 618

def render_inline_unsafe(statement)
  return nil unless statement.body.length == 1

  nested = statement.body.first
  return nil if nested.is_a?(AST::LocalDecl)

  inline = render_inline_statement(nested)
  return nil unless inline
  return nil if unsafe_inline_trivia_conflict?(statement, nested)

  "unsafe: #{inline}"
end

#render_interface_method_signature(method) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 411

def render_interface_method_signature(method)
  prefix = +""
  prefix << "async " if method.async
  prefix << case method.kind
  when :editable
    "editable function "
  else
    "function "
  end

  text = "#{prefix}#{method.name}(#{method.params.map { |param| render_param(param) }.join(', ')})"
  text << " -> #{render_type(method.return_type)}" if method.return_type
  text
end

#render_is_expression(expression, parent_precedence) ⇒ Object

expr is Arm desugars at parse time to match expr: Arm: true; _: false; re-sugar that exact shape back to is so the formatter round-trips (and a multi-line match does not break when used as a statement condition).



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 879

def render_is_expression(expression, parent_precedence)
  arms = expression.arms
  return nil unless arms.length == 2

  first, second = arms
  return nil if first.binding_name || second.binding_name
  return nil unless boolean_literal?(first.value, true) && boolean_literal?(second.value, false)
  return nil unless wildcard_pattern?(second.pattern)
  return nil if first.pattern.is_a?(AST::Call) && first.pattern.arguments.any?

  scrutinee = render_expression(expression.expression, IS_PRECEDENCE)
  arm = render_expression(first.pattern, IS_PRECEDENCE)
  wrap("#{scrutinee} is #{arm}", parent_precedence, IS_PRECEDENCE)
end

#render_list_element(element) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 840

def render_list_element(element)
  return render_argument(element) if element.is_a?(AST::Argument)

  render_expression(element)
end

#render_param(param) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 696

def render_param(param)
  if param.is_a?(AST::ForeignParam)
    text = +""
    text << "#{param.mode} " unless param.mode == :plain
    text << "#{param.name}: #{render_type(param.type)}"
    text << " as #{render_type(param.boundary_type)}" if param.boundary_type
    return text
  end

  return param.name unless param.type

  "#{param.name}: #{render_type(param.type)}"
end

#render_postfix(expression) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 902

def render_postfix(expression)
  return render_expression(expression, POSTFIX_PRECEDENCE) if postfix_expression?(expression)

  "(#{render_expression(expression)})"
end

#render_signature_params(function) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 332

def render_signature_params(function)
  params = function.params.map { |param| render_param(param) }
  params << "..." if function.respond_to?(:variadic) && function.variadic
  params.join(', ')
end

#render_struct_params(lifetime_params, type_params) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 353

def render_struct_params(lifetime_params, type_params)
  parts = []
  parts.push(*lifetime_params) if lifetime_params&.any?
  parts.concat(type_params.map(&:name))
  return "" if parts.empty?

  "[#{parts.join(', ')}]"
end

#render_type(type) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 710

def render_type(type)
  case type
  when AST::TypeRef
    text = type.name.to_s
    args = []
    args << type.lifetime if type.lifetime
    args.concat(type.arguments.map { |argument| render_type_argument(argument.value) })
    text += "[#{args.join(', ')}]" unless args.empty?
    type.nullable ? "#{text}?" : text
  when AST::FunctionType
    "fn(#{type.params.map { |param| render_param(param) }.join(', ')}) -> #{render_type(type.return_type)}"
  when AST::ProcType
    "proc(#{type.params.map { |param| render_param(param) }.join(', ')}) -> #{render_type(type.return_type)}"
  when AST::DynType
    if type.interface.type_arguments.any?
      "dyn[#{type.interface.parts.join('.')}[#{type.interface.type_arguments.map { |a| render_type(a) }.join(', ')}]]"
    else
      "dyn[#{type.interface.parts.join('.')}]"
    end
  when AST::TupleType
    text = "(#{type.element_types.map { |element| render_type(element) }.join(', ')})"
    type.nullable ? "#{text}?" : text
  else
    type.to_s
  end
end

#render_type_argument(argument) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 737

def render_type_argument(argument)
  case argument
  when AST::IntegerLiteral, AST::FloatLiteral
    argument.lexeme
  else
    render_type(argument)
  end
end

#render_type_param_constraints(constraints) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 362

def render_type_param_constraints(constraints)
  parts = []
  index = 0
  while index < constraints.length
    constraint = constraints[index]
    if constraint.kind == :interface
      interfaces = [constraint.interface_ref.to_s]
      index += 1
      while index < constraints.length && constraints[index].kind == :interface
        interfaces << constraints[index].interface_ref.to_s
        index += 1
      end
      parts << "implements #{interfaces.join(' and ')}"
    else
      raise "unsupported type parameter constraint #{constraint.kind}"
    end
  end

  parts.join(' and ')
end

#render_type_params(type_params) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 338

def render_type_params(type_params)
  return "" if type_params.empty?

  rendered = type_params.map do |type_param|
    if type_param.is_a?(AST::ValueTypeParam)
      next "#{type_param.name}: #{render_type(type_param.type)}"
    end

    next type_param.name if type_param.constraints.empty?

    "#{type_param.name} #{render_type_param_constraints(type_param.constraints)}"
  end
  "[#{rendered.join(', ')}]"
end

#unsafe_inline_trivia_conflict?(unsafe_stmt, nested) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 663

def unsafe_inline_trivia_conflict?(unsafe_stmt, nested)
  unsafe_line = unsafe_stmt.line
  nested_line = nested&.line
  return false unless unsafe_line && nested_line && nested_line > unsafe_line

  @comment_map.keys.any? { |line| line >= unsafe_line + 1 && line <= nested_line } ||
    @blank_line_set.keys.any? { |line| line >= unsafe_line + 1 && line < nested_line }
end

#visibility_prefix(declaration_or_visibility) ⇒ Object 



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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 320

def visibility_prefix(declaration_or_visibility)
  return "" if @current_module_kind == :raw_module

  visibility = if declaration_or_visibility.is_a?(Symbol)
    declaration_or_visibility
  elsif declaration_or_visibility.respond_to?(:visibility)
    declaration_or_visibility.visibility
  end

  visibility == :public ? "public " : ""
end

#wildcard_pattern?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/core/pretty_printer/ast_formatter.rb', line 898

def wildcard_pattern?(node)
  node.is_a?(AST::Identifier) && node.name == "_"
end