map is:exact -package:aeson -package:Cabal-syntax -package:base-prelude -package:containers -package:monoidal-containers -package:incipit-base -package:hedgehog -package:amazonka-core -package:bytestring -package:dlist package:pipes

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

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