:: Eq a => [a] -> a -> Bool -package:vector -package:numeric-prelude -package:hledger -package:rio -package:protolude package:Agda
Check membership for the same list often. Use partially applied to
create membership predicate
hasElem xs :: a -> Bool.
- First time: O(n log n) in the worst case.
- Subsequently: O(log n).
Specification:
hasElem xs == (elem xs).
A generalised variant of elemIndex. O(n).