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