// Deterministic shuffled list iterator using an XORSHIFT RNG
// Each step is O(1), iterator is OSPACE(1)

sclass WeightlessShuffledIterator<A> extends ItIt<A> {
  final int n;
  int i;
  TripletLSFR lsfr;

  *(L<A> l) {
    n = l(l);
    if (n == 0) ret;
    int bits = numberOfBitsNeededToRepresentNOptions(l);
    lsfr = new TripletLSFR(bits);
  }
  
  public bool hasNext() { ret i < n; }
  
  public A next() {
    int raw;
    do
      raw = lsfr.next()-1;
    while (raw >= n);
    ret raw;
  };
}