map is:exact -package:text -package:Cabal-syntax -package:dense-linear-algebra -package:charset -package:case-insensitive -package:dlist -package:blaze-html -package:aeson -package:hedgehog -package:amazonka-core -package:base-prelude -package:bytestring package:basement
Map all element a from a block to a new block of b
Map all elements in a list