static L<IntRange> parseHexRanges(S s) {
  ret map(splitAtComma_trim(s), item -> {
    LS parts = splitAtMinus(item);
    int start = hexToInt(first(parts));
    if (l(parts) == 1)
      ret intRange_incl(start, start);
    else if (l(parts) == 2) {
      int end = hexToInt(second(parts));
      ret intRange_incl(start, end);
    } else
      fail("Too many minuses");
  });
}