static IterableIterator<S> gWants() {
  final L<S> log = gLog();
  
  ret new IterableIterator<S>() {
    int i = l(log);

    public bool hasNext() {
      while (--i >= 0 && !swic(get(log, i), "[want]"));
      ret i >= 0;
    }
    
    public S next() {
      ret dropPrefixICTrim("[want]", get(log, i));
    }
  };
}