foldRightWithIndex<B> method
Implementation
B foldRightWithIndex<B>(B b, B Function(int i, B acc, A a) f) =>
foldRight<Tuple2<B, int>>(
Tuple2(b, length() - 1),
(t, a) => Tuple2(f(t.second, t.first, a), t.second - 1),
).first;