grammar CommandLine
  rule command
    name (delimited_option / delimited_argument)* {
      def option_list
        opts = self.elements[1].elements.inject([]) do |a, e|
          a << e.opt_value
        end
        opts.compact
      end

      def argument_list
        args = self.elements[1].elements.inject([]) do |a, e|
          a << e.arg_value
        end
        args.compact
      end
    }
  end

  rule name
    argument
  end

  rule delimited_option
    ' ' option {
      def opt_value
        self.option.opt_value
      end
      
      def arg_value
        self.option.arg_value
      end
    }
  end

  rule delimited_argument
    ' ' argument {
      def opt_value
        nil
      end
      
      def arg_value
        self.argument.text_value
      end
    }
  end

  rule option
    (long_option / short_option)
  end

  rule long_option
    '--' (opt_name '=' argument / opt_name) {
      def opt_value
        self.elements[1].respond_to?(:opt_name) ?
          self.elements[1].opt_name.text_value : self.elements[1].text_value
      end

      def arg_value
        self.elements[1].respond_to?(:opt_name) ?
          self.elements[1].argument.text_value : nil
      end
    }
  end

  rule short_option
    '-' (label_char '=' argument / opt_name) {
    def opt_value
      self.elements[1].respond_to?(:label_char) ?
        self.elements[1].label_char.text_value : self.elements[1].text_value
    end

    def arg_value
      self.elements[1].respond_to?(:label_char) ?
        self.elements[1].argument.text_value : nil
    end
    }
  end

  rule argument
    (quoted_chars / unquoted_chars) {
      def arg_value
        self.text_value
      end
    }
  end

  rule opt_name
    label_char+
  end

  rule label_char
    [a-zA-Z0-9]
  end

  rule quoted_chars
    '"' (!'"' . / '\"')* '"'
  end

  rule unquoted_chars
    (!' ' . / '\ ')+
  end

end