map is:exact -package:vector -package:bytestring -package:dlist -package:aeson -package:containers -package:foldl -package:monoidal-containers -package:base-prelude -package:integration -package:ghc -package:base-compat-batteries -package:case-insensitive package:basement
Map all element a from a block to a new block of b
Map all elements in a list