map -package:containers -is:exact -package:insert-ordered-containers -package:base-compat -package:monoidal-containers -package:ghc -package:Cabal-syntax -package:base-prelude is:exact -package:foldl -package:invertible -package:conduit -package:os-string package:basement
Map all element a from a block to a new block of b
Map all elements in a list