static L<S dropSuffixUsingWordTree_all(L<S> tok, Map<S, O> tree) {

}

// tok = CNC

// returns [(index, tree leaf)]

static LPair<Int, O> matchEndUsingWordTree_all(L<S> tok, Map<S, O> tree) {

  O best = null; // best leaf

  int bestIndex = 0; // best index

  int j = l(tok)-2;

  LPair<Int, O> out = new L;

  while (j > 0) {

    O def = tree.get("<default>");

    if (def != null) { best = def; bestIndex = j; }

    O t = tree.get(tok.get(j));

    if (t == null) break;

    if (!t instanceof Map) break with addPair(out, j, t); // leaf!

    j -= 2;

    tree = (Map) t;

  }

  if (best != null) addPair(out, bestIndex, best);

  ret out;

}