code: def and_next(e):
      
      def match_and_next(s, grm=None, pos=0):
          try:
              e(s, grm, pos)
          except PegreError as ex:
              raise PegreError('Positive lookahead failed', pos)
          else:
              return PegreResult(s, Ignore, (pos, pos))
      return match_and_next
docs: Create a PEG function for positive lookahead.