Extensions to the set API, which utilise typeclasses.
fold : Typeclasses.Classes.Monoid.Monoid a -> Set a -> a
O(n). Combine the elements of set using a Monoid
instance.
foldMap : Typeclasses.Classes.Monoid.Monoid b -> (a -> b) -> Set a -> b
O(n). Map each element of the set to a type which has an instance of Monoid
,
and combine the results.