Class: Lexer

Inherits:
Object
  • Object
show all
Defined in:
lib/filipinomemes/ruby_parser_patches.rb

Overview

Lexer The Parsing method is explicitly UTF-8 so the Lexer is also explicitly UTF-8 Inorder to use the functions of yacc, we need to use BNF Grammar

Instance Method Summary collapse

Instance Method Details

#parse_number ⇒ Object 



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# File 'lib/filipinomemes/ruby_parser_patches.rb', line 5

def parse_number
  self.lex_state = :expr_end

  if src.scan(/[+-]?0[xXbBdD]\b/)
    rb_compile_error 'Invalid numeric format'
  # elsif src.scan(/[+-]?(?:(?:[1-9][\d_]*|0)(?!\.\d)\b|0[Dd][0-9_]+)/)
  elsif src.scan(/[+-]?(?:(?:[1-9][\d_]*|0)(?!\,\d)\b|0[Dd][0-9_]+)/)
    int_with_base(10)
  elsif src.scan(/[+-]?0x[a-f0-9_]+/i)
    int_with_base(16)
  elsif src.scan(/[+-]?0[Bb][01_]+/)
    int_with_base(2)
  elsif src.scan(/[+-]?0[Oo]?[0-7_]*[89]/)
    rb_compile_error 'Illegal octal digit.'
  elsif src.scan(/[+-]?0[Oo]?[0-7_]+|0[Oo]/)
    int_with_base(8)
  elsif src.scan(/[+-]?[\d_]+_(e|\.)/)
    rb_compile_error "Trailing '_' in number."
  # elsif src.scan(/[+-]?[\d_]+\.[\d_]+(e[+-]?[\d_]+)?\b|[+-]?[\d_]+e[+-]?[\d_]+\b/i)
  elsif src.scan(/[+-]?[\d_]+\,[\d_]+(e[+-]?[\d_]+)?\b|[+-]?[\d_]+e[+-]?[\d_]+\b/i)
    number = src.matched.sub(',', '.')
    rb_compile_error 'Invalid numeric format' if number =~ /__/
    self.yacc_value = number.to_f
    #values of token which had a value associated with it.
    :tFLOAT
  elsif src.scan(/[+-]?[0-9_]+(?![e])/)
    int_with_base(10)
  else
    rb_compile_error 'Bad number format'
  end
end