worst_s_exp_parser_literally_ever_conceived.rb

worst_s_exp_parser_literally_ever_conceived.rb

 def lex(str, tokens=[])
  str.is_a?(String) ?
    lex(StringScanner.new(str))
  :
    (str.scan(/\(/) ?
      lex(str, tokens << :l_paren)
    :
      (str.scan(/\)/) ?
        lex(str, tokens << :r_paren)
      :
        ((token = str.scan(/\s+/)) ?
          lex(str, tokens)
        :
          ((token = str.scan(/"(?:[^"\\]|\\.)*"/) ?
            lex(str, tokens << [:string, token])
          :
            ((token = str.scan(/\d+/)) ?
              lex(str, tokens << [:digit, token.to_i])
            :
              ((token = str.scan(/;.*\n/)) ?
                lex(str, tokens << [:comment])
              :
                ((token = str.scan(/[A-z][\-A-z0-9]*/)) ?
                  lex(str, tokens << [:word, token])
                :
                  ((token = str.scan(/[+\-\&\*\%\$\#\!\^\:\>\<\.\,\?\=]+/)) ?
                    lex(str, tokens << [:special_token, token])
                  :
                    (str.eos? ?
                    tokens
                    :
                      (raise "Unexpected token")))))))))))
end