sort method

Selection sort(Comparator<JSAny?> compare)

Returns a new selection that contains a copy of each group in this selection sorted according to the compare function. After sorting, re-inserts elements to match the resulting order (per selection.order).

The compare function, which defaults to ascending, is passed two elements’ data a and b to compare. It should return either a negative, positive, or zero value. If negative, then a should be before b; if positive, then a should be after b; otherwise, a and b are considered equal and the order is arbitrary.

Implementation

Selection sort(Comparator<JSAny?> compare) {
  int compareNode(Element? a, Element? b) {
    var aIsNull = (a == null ? 1 : 0),
        bIsNull = (b == null ? 1 : 0),
        xor = aIsNull - bIsNull;
    return xor == 0 && aIsNull == 0
        ? compare((a as JSObject)["__data__"], (b as JSObject)["__data__"])
        : xor;
  }

  final m = _groups.length, sortgroups = List<List<Element?>>.filled(m, []);
  for (var j = 0; j < m; ++j) {
    Element? node;
    List<Element?> group = _groups[j];
    int n = group.length;
    List<Element?>? sortgroup =
        sortgroups[j] = List<Element?>.filled(n, null);
    for (var i = 0; i < n; ++i) {
      if ((node = group[i]) != null) {
        sortgroup[i] = node;
      }
    }
    sortgroup.sort(compareNode);
  }

  return Selection._(sortgroups, _parents)..order();
}