static IterableIterator<L<Int>> allSpreads(final int toSpread, final int buckets) {
  class StackEntry {
    int remaining, n, take;
    L<Int> collecting;
    int position;
    
    O step(L<StackEntry> stack) {
      if (position == 0) {
        if (l(collecting) >= n-1) {
          L<Int> result = listPlus(collecting, remaining);
          dropLast(stack);
          ret result;
        }
        position++;
      } else if (position == 1) {
        if (take <= remaining) {
          collecting.add(take);
          new StackEntry e;
          e.remaining = remaining-take;
          e.n = n;
          e.collecting = collecting;
          stack.add(e);
          position++;
        } else
          dropLast(stack);
      } else if (position == 2) {
        removeLast(collecting);
        take++;
        position = 1;
      }
      null;
    }
  }
  
  final new L<StackEntry> stack;
  new StackEntry e;
  e.n = buckets;
  e.remaining = toSpread;
  e.collecting = new L;
  stack.add(e);
  
  ret iff(func {
    while (nempty(stack)) {
      ping();
      try object last(stack).step(stack);
    }
    ret endMarker();
  });
}