6 | record HashSet k where
7 | constructor MkHashSet
8 | hashmap: HashMap k ()
11 | empty : Hashable k => Eq k => HashSet k
12 | empty = MkHashSet empty
15 | insert : Hashable k => Eq k => k -> HashSet k -> HashSet k
16 | insert k = { hashmap $= insert k () }
19 | contains : Hashable k => Eq k => k -> HashSet k -> Bool
20 | contains k (MkHashSet hm) = isJust $
lookup k hm