map is:exact -package:conduit -package:bytestring -package:foldl -package:Cabal-syntax -package:monoidal-containers -package:charset -package:base-compat-batteries -package:blaze-html -package:aeson -package:os-string -package:base-prelude package:basement
Map all element a from a block to a new block of b
Map all elements in a list