Class: Vernacular::ASTModifier

Inherits:
Object
  • Object
show all
Defined in:
lib/vernacular/ast_modifier.rb

Overview

Represents a modification that will be performed against the AST between the time that the source code is read and the time that it is compiled down to YARV instruction sequences.

Defined Under Namespace

Classes: BuilderExtension, ParserExtension

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize {|_self| ... } ⇒ ASTModifier

Returns a new instance of ASTModifier.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/vernacular/ast_modifier.rb', line 24

def initialize
  @builder_extensions = []
  @parser_extensions = []
  yield self if block_given?
end

Instance Attribute Details

#builder_extensions ⇒ Object (readonly)

Returns the value of attribute builder_extensions.



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# File 'lib/vernacular/ast_modifier.rb', line 12

def builder_extensions
  @builder_extensions
end

#parser_extensions ⇒ Object (readonly)

Returns the value of attribute parser_extensions.



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# File 'lib/vernacular/ast_modifier.rb', line 20

def parser_extensions
  @parser_extensions
end

#rewriter_block ⇒ Object (readonly)

Returns the value of attribute rewriter_block.



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# File 'lib/vernacular/ast_modifier.rb', line 22

def rewriter_block
  @rewriter_block
end

Instance Method Details

#build_rewriter(&block) ⇒ Object 



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# File 'lib/vernacular/ast_modifier.rb', line 30

def build_rewriter(&block)
  @rewriter_block = block
end

#components ⇒ Object 



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# File 'lib/vernacular/ast_modifier.rb', line 55

def components
  (builder_extensions + parser_extensions).flat_map(&:components) +
    rewriter_block.source_location
end

#extend_builder(method, &block) ⇒ Object 



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# File 'lib/vernacular/ast_modifier.rb', line 34

def extend_builder(method, &block)
  builder_extensions << BuilderExtension.new(method, block)
end

#extend_parser(symbol, pattern, code) ⇒ Object 



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# File 'lib/vernacular/ast_modifier.rb', line 38

def extend_parser(symbol, pattern, code)
  parser_extensions << ParserExtension.new(symbol, pattern, code)
end

#modify(source) ⇒ Object 



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# File 'lib/vernacular/ast_modifier.rb', line 42

def modify(source)
  raise 'You must first configure a rewriter!' unless rewriter_block

  rewriter = Class.new(Parser::Rewriter, &rewriter_block).new
  rewriter.instance_variable_set(:@parser, ASTParser.parser)

  buffer = Parser::Source::Buffer.new('<dynamic>')
  buffer.source = source

  ast = ASTParser.parse(source)
  rewriter.rewrite(buffer, ast)
end