Class: CodeRay::WordList

Inherits:
Hash
  • Object
show all
Defined in:
lib/coderay/helpers/word_list.rb

Overview

WordList

A Hash subclass designed for mapping word lists to token types.

A WordList is a Hash with some additional features. It is intended to be used for keyword recognition.

WordList is optimized to be used in Scanners, typically to decide whether a given ident is a special token.

For case insensitive words use WordList::CaseIgnoring.

Example:

define word arrays

RESERVED_WORDS = %w[ asm break case continue default do else ]

PREDEFINED_TYPES = %w[ int long short char void ]

make a WordList

IDENT_KIND = WordList.new(:ident). add(RESERVED_WORDS, :reserved). add(PREDEFINED_TYPES, :predefined_type)

...

def scan_tokens tokens, options ...

elsif scan(/[A-Za-z_][A-Za-z_0-9]*/)
 # use it
 kind = IDENT_KIND[match]
 ...

Direct Known Subclasses

CaseIgnoring

Defined Under Namespace

Classes: CaseIgnoring

Instance Method Summary collapse

Constructor Details

#initialize(default = false) ⇒ WordList

Create a new WordList with default as default value.



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# File 'lib/coderay/helpers/word_list.rb', line 43

def initialize default = false
  super default
end

Instance Method Details

#add(words, value = true) ⇒ Object

Add words to the list and associate them with value.

Returns self, so you can concat add calls.



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# File 'lib/coderay/helpers/word_list.rb', line 50

def add words, value = true
  words.each { |word| self[word] = value }
  self
end