map -package:Cabal -package:base -package:text package:unordered-containers is:exact

O(n) Transform this map by applying a function to every value.
O(n) Transform this set by applying a function to every value. The resulting set may be smaller than the source.
>>> HashSet.map show (HashSet.fromList [1,2,3])
HashSet.fromList ["1","2","3"]