map is:exact -package:text -package:containers -package:blaze-html -package:case-insensitive -package:base-prelude -package:incipit-base -package:aeson -package:base-compat-batteries -package:imports -package:ghc -package:filepath -package:monoidal-containers package:basement
Map all element a from a block to a new block of b
Map all elements in a list