map is:exact -package:text -package:charset -package:conduit -package:foldl -package:basement -package:base -package:containers -package:psqueues -package:filepath -package:hedgehog package:unordered-containers

Transform this map by applying a function to every value.
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"]