findUnsafe method

@override int? findUnsafe(F target, num? tolerance, int start, int end,)

Internal implementation for find, which does not do any validity checks on its arguments. Not to be called directly.

Implementation

@override
int? findUnsafe(F target, num? tolerance, int start, int end) {
  // Check that it's necessary and possible to deal with tolerances.
  final supportTolerance =
      tolerance != null && tolerance != 0 && compareDiff.diffFunc != null;

  int? bestIndexWithinTolerance;
  num? bestDiffWithinTolerance;

  // Slow implementation, as we've got to do a linear search.
  for (var i = start; i < end; i++) {
    if (compareDiff.compareFunc(collection, i, target) == 0) {
      return i;
    }

    if (supportTolerance) {
      final diff = compareDiff.diffFunc!(collection, i, target).abs();
      if (diff > tolerance) {
        continue;
      }
      if (bestDiffWithinTolerance == null || diff < bestDiffWithinTolerance) {
        bestDiffWithinTolerance = diff;
        bestIndexWithinTolerance = i;
      }
    }
  }

  // Did not find perfect match, but maybe found something within tolerance.
  if (bestIndexWithinTolerance != null) {
    return bestIndexWithinTolerance;
  }

  // Linear search delivered nothing -> return null.
  return null;
}