map -package:base -is:exact -is:exact -package:case-insensitive -package:aeson -package:conduit package:unordered-containers -is:exact is:exact
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])