map -package:containers -package:ghc -package:incipit-base -package:dense-linear-algebra is:exact -package:charset -package:hedgehog -package:monoidal-containers -package:amazonka-core -package:os-string -package:base-compat-batteries package:pipes

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

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