map -package:containers -package:aeson -package:incipit-base -package:charset -package:insert-ordered-containers -package:blaze-html -package:bytestring -package:base-compat -package:case-insensitive -package:dlist -package:base-compat-batteries package:basement is:exact
Map all element a from a block to a new block of b
Map all elements in a list