reduceIndexed
inline fun <E : Any> EntitySequence<E, *>.reduceIndexed(operation: (index: Int, acc: E, E) -> E): E(source)
Accumulate value starting with the first element and applying operation from left to right to current accumulator value and each element with its index in the original sequence.
Throws an exception if this sequence is empty. If the sequence can be empty in an expected way, please use reduceIndexedOrNull instead. It returns null when its receiver is empty.
The operation function takes the index of an element, current accumulator value and the element itself and calculates the next accumulator value.
The operation is terminal.
