map -package:containers -package:basement -package:conduit -is:exact -package:insert-ordered-containers -package:monoidal-containers -package:aeson -package:bytestring -package:invertible -package:text -package:dlist -package:foldl -package:vector -package:blaze-html 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