static IterableIterator<L<Int>> allSpreads(final int toSpread, final int buckets) {
  class StackEntry {
    int remaining, n, take;
    L<Int> collecting;
    int position;
    
    L<Int> step(L<StackEntry> stack) {
      if (position == 0) {
        if (l(collecting) >= n-1) {
          result = listPlus(cloneList(collecting), remaining);
          dropLast(stack);
          ret result;
        }
        position = 1;
      } 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);
        } else {
          if (empty(stack)) ret endMarker();
          dropLast(stack);
        }
      } else if (e.position == 2) {
        removeLast(e.collecting);
        e.take++;
        e.position = 1;
      }
    }
  }
  
  final new L<StackEntry> stack;
  new StackEntry e;
  e.n = buckets;
  e.remaining = toSpread;
  e.collecting = new L;
  stack.add(e);
  
  ret iff(new F0 {
    while true {
      ping();
      L<Int> result = last(stack).step(stack);
      if (result != null) ret result;
    }
  });
}