map is:exact -package:bytestring -package:dlist -package:blaze-html -package:aeson -package:Cabal-syntax -package:case-insensitive -package:charset -package:insert-ordered-containers -package:hedgehog -package:os-string -package:monoidal-containers package:basement
Map all element a from a block to a new block of b
Map all elements in a list