'Test if a the current regex trigger matches `trigger`.
If so, set _last_re and _matched.'

def _re_match(self, trigger):

    for match in re.finditer(self._trigger, trigger):
        if (match.end() != len(trigger)):
            continue
        else:
            self._matched = trigger[match.start():match.end()]
        self._last_re = match
        return match
    return False
