map is:exact -package:aeson -package:conduit -package:case-insensitive -package:base-compat-batteries -package:amazonka-core -package:blaze-html -package:insert-ordered-containers -package:dense-linear-algebra -package:incipit-base -package:invertible -package:base package:basement
Map all element a from a block to a new block of b
Map all elements in a list