map -package:containers -package:bytestring -package:basement -package:base -package:foldl -package:monoidal-containers -package:ghc -package:Cabal-syntax -package:charset -package:os-string -package:text -package:base-compat-batteries -package:case-insensitive -package:regex-tdfa -package:insert-ordered-containers -package:conduit -package:filepath 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