map -package:containers -package:Cabal-syntax -package:basement -package:psqueues -package:insert-ordered-containers -package:bytestring -package:os-string -package:regex-tdfa -package:filepath -package:charset -package:vector -package:incipit-base package:vector-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