map is:exact -package:text -package:Cabal-syntax -package:dlist -package:foldl -package:case-insensitive -package:base -package:filepath -package:dense-linear-algebra -package:base-compat -package:base-compat-batteries -package:incipit-base -package:imports package:basement
Map all element a from a block to a new block of b
Map all elements in a list