map -package:containers -package:Cabal-syntax -package:bytestring -package:base-prelude is:exact -package:aeson -package:foldl -package:hedgehog -package:monoidal-containers -package:incipit-base -package:case-insensitive package:pipes

Apply a function to all values flowing downstream
map id = cat

map (g . f) = map f >-> map g