reduceRightIndexed<S> method

S reduceRightIndexed<S>(
  1. S operation(
    1. int index,
    2. T,
    3. S acc
    )
)

Accumulates value starting with last element and applying operation from right to left to each element with its index in the original list and current accumulator value. @param operation function that takes the index of an element, the element itself and current accumulator value, and calculates the next accumulator value.

Implementation

S reduceRightIndexed<S>(S Function(int index, T, S acc) operation) {
  final i = listIterator(size);
  if (!i.hasPrevious()) {
    throw UnimplementedError("Empty list can't be reduced.");
  }
  var accumulator = i.previous() as S;
  while (i.hasPrevious()) {
    accumulator = operation(i.previousIndex(), i.previous(), accumulator);
  }
  return accumulator;
}