static boolean find3(S pat, S s) {
  return find3(pat, s, null);
}

static boolean find3(S pat, S s, Matches matches) {
  L<S> tokpat = parse3(pat), toks = parse3(s);
  S[] m = find2(tokpat, toks);
  //print(structure(tokpat) + " on " + structure(toks) + " => " + structure(m));
  if (m == null)
    return false;
  else {
    if (matches != null) matches.m = m;
    return true;
  }
}