Class: Dhaka::Lexeme

Inherits:
Object
  • Object
show all
Defined in:
lib/lexer/lexeme.rb

Overview

Represents a portion of the input string that has been recognized as matching a given lexer pattern.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(input_position) ⇒ Lexeme

:nodoc:



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# File 'lib/lexer/lexeme.rb', line 11

def initialize(input_position) #:nodoc:
  @input_position = input_position
  @characters = []
end

Instance Attribute Details

#characters ⇒ Object (readonly)

Returns the value of attribute characters.



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# File 'lib/lexer/lexeme.rb', line 9

def characters
  @characters
end

#input_position ⇒ Object (readonly)

input_position is the index in the input stream that this lexeme starts at.



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# File 'lib/lexer/lexeme.rb', line 8

def input_position
  @input_position
end

#pattern ⇒ Object

The pattern matched by this lexeme.



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# File 'lib/lexer/lexeme.rb', line 5

def pattern
  @pattern
end

Instance Method Details

#<<(char) ⇒ Object

:nodoc:



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# File 'lib/lexer/lexeme.rb', line 25

def << char #:nodoc:
  @characters << char
end

#accepted? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/lexer/lexeme.rb', line 21

def accepted? #:nodoc:
  pattern
end

#concat(chars) ⇒ Object

:nodoc:



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# File 'lib/lexer/lexeme.rb', line 29

def concat chars #:nodoc:
  @characters.concat chars
end

#value ⇒ Object

The substring of the input stream that this lexeme is comprised of.



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# File 'lib/lexer/lexeme.rb', line 17

def value
  characters.join
end