map is:exact -package:text -package:containers -package:dlist -package:insert-ordered-containers -package:base-compat -package:incipit-base -package:integration -package:ghc -package:monoidal-containers -package:Cabal-syntax -package:os-string -package:psqueues package:basement
Map all element a from a block to a new block of b
Map all elements in a list