rsplitn method
Returns an iterator over slices separated by elements that match pred, limited to returning at most n items, starting from the end. The matched element is not contained in the slices. The last element returned, if any, will contain the remainder of the slice.
Implementation
Iter<Slice<T>> rsplitn(int n, bool Function(T) pred) {
if (n < 0) {
panic("'n' cannot be negative");
}
return Iter(_rsplitnHelper(n, pred).iterator);
}