Class: TRuby::ParserCombinator::TokenOptional

Inherits:
TokenParser
  • Object
show all
Defined in:
lib/t_ruby/parser_combinator/token/token_optional.rb

Overview

Optional: zero or one

Instance Method Summary collapse

Methods inherited from TokenParser

#<<, #>>, #label, #many, #many1, #map, #optional, #sep_by, #sep_by1, #|

Constructor Details

#initialize(parser) ⇒ TokenOptional

Returns a new instance of TokenOptional.



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# File 'lib/t_ruby/parser_combinator/token/token_optional.rb', line 7

def initialize(parser)
  @parser = parser
end

Instance Method Details

#parse(tokens, position = 0) ⇒ Object 



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# File 'lib/t_ruby/parser_combinator/token/token_optional.rb', line 11

def parse(tokens, position = 0)
  result = @parser.parse(tokens, position)
  if result.success?
    result
  else
    TokenParseResult.success(nil, tokens, position)
  end
end