map is:exact -package:text -package:charset -package:conduit -package:foldl -package:base-prelude -package:insert-ordered-containers -package:blaze-html -package:filepath -package:Cabal-syntax -package:case-insensitive -package:ghc -package:dlist package:basement
Map all element a from a block to a new block of b
Map all elements in a list