Class: Vernacular::AST::Modifier

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| ... } ⇒ Modifier

Returns a new instance of Modifier.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/vernacular/ast/modifier.rb', line 27

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 15

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 23

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 25

def rewriter_block
  @rewriter_block
end

Instance Method Details

#build_rewriter(&block) ⇒ Object 



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# File 'lib/vernacular/ast/modifier.rb', line 33

def build_rewriter(&block)
  @rewriter_block = block
end

#components ⇒ Object 



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# File 'lib/vernacular/ast/modifier.rb', line 58

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 37

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 41

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 45

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

  rewriter = Class.new(Parser::TreeRewriter, &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