map -package:containers -package:bytestring -package:dlist -package:base-prelude -package:basement -package:incipit-base -package:filepath -package:os-string -package:conduit -package:regex-tdfa -package:psqueues -package:vector 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