<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _uncached_match(self, text, pos, cache, error):
 """Return length of match, ``None`` if no match."""

        m = self.re.match(text, pos)
        if m is not None:
            span = m.span()
            node = RegexNode(self, text, pos, pos + span[1] - span[0])
            node.match = m  # TODO: A terrible idea for cache size?
            return node