runningReduce method
Returns a Iterable containing successive accumulation values generated
by applying combine
function from left to right to each element and
current accumulator value that starts with the first element of this
collection.
Implementation
Iterable<E> runningReduce(E Function(E value, E element) combine) {
if (isEmpty) return Iterable.empty();
E value = first;
return skip(1).map((element) {
value = combine(value, element);
return value;
});
}