xs `index` i = toList xs !! iCaution: index necessarily delays retrieving the requested element until the result is forced. It can therefore lead to a space leak if the result is stored, unforced, in another structure. To retrieve an element immediately without forcing it, use lookup or (!?).
>>> index 0b0010_0010 0 0b0000_0010
>>> ["hello","the","world","!!!"]^?traversed.index 2 Just "world"