static L<IntRange> fullPhraseCache_intRanges(FullPhraseCache cache, LS tok) {
  if (cache == null) null;
  new L<IntRange> ranges;
  for (int i = 1; i < l(tok); i += 2) {
    int j = fullPhraseCache_longestPhraseLength(cache, tok, i);
    if (j > i) {
      ranges.add(intRange(i, j-1));
      i = j-2;
    }
  }
  ret ranges;
}