// Allows to vary the order by supplying a seed
//
// We add the seed to every LSFR value generated, and also start
// the LSFR with the seed.

// Not 100% sure if this works, there was an endless loop once

sclass WeightlessShuffledIteratorWithSeed<A> extends WeightlessShuffledIterator<A> {
  final int offset;
  
  // initialize only with a length (and a pseudo-list)
  // if you are going to be calling nextIndex() instead of next()
  *(int n) {
    this((L) iotaZeroList(n));
  }
  
  *(int n, int seed) {
    this((L) iotaZeroList(n), seed);
  }
  
  *(L<A> list) {
    this(list, 0);
  }

  *(L<A> list, int seed) {
    super(list);
    if (n == 0) ret with offset = 0;
    lsfr_start(seed);
    offset = value-1;
  }
  
  // copied from TripletLSFR.start
  void lsfr_start(int seed) {
    value = mod_31bit(seed, cycleLength)+1;
  }
  
  int postProcessLSFRValue(int i) {
    i += offset;
    ret i >= cycleLength ? i-cycleLength : i;
  }
}

Began life as a copy of #1035206