code: def reject(self, f, *args):
          
          match = self.match(f, *args)
          if match:
              token = self.peek(0)
              raise errors.EfilterParseError(
                  query=self.tokenizer.source, token=token,
                  message="Was not expecting a %s here." % token.name)
docs: Like 'match', but throw a parse error if 'f' matches.
  
          This is useful when a parser wants to be strict about specific things
          being prohibited. For example, DottySQL bans the use of SQL keywords as
          variable names.