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