code: def space():
      '''Parser a whitespace character.'''
      @Parser
      def space_parser(text, index=0):
          if index < len(text) and text[index].isspace():
              return Value.success(index + 1, text[index])
          else:
              return Value.failure(index, 'one space')
      return space_parsef space():
      '''Parser a whitespace character.'''
      @Parser
      def space_parser(text, index=0):
          if index < len(text) and text[index].isspace():
              return Value.success(index + 1, text[index])
          else:
              return Value.failure(index, 'one space')
      return space_parser
docs: Parser a whitespace character.