static bool endsWithIgnoreCase(S a, S b) {
  ret l(a) >= l(b) && regionMatchesIC(l(a)-l(b), b, 0, l(b));
}

static bool endsWithIgnoreCase(S a, S b, Matches m) {
  if (!endsWithIgnoreCase(a, b)) false;
  m.m = new S[] { substring(a, 0, l(a)-l(b)) };
  true;
}