map -package:containers -package:insert-ordered-containers -package:basement -package:monoidal-containers -package:psqueues -package:conduit -package:ghc -package:imports -package:text -is:exact -package:regex-tdfa -package:vector -package:dlist package:vector-stream

Map a function over a Stream
Map a monadic function over a Stream
Execute a monadic action for each element of the Stream
Apply monadic function to each element and drop all Nothings