map -package:containers -package:insert-ordered-containers -package:ghc -package:dense-linear-algebra -package:foldl -package:incipit-base -package:hedgehog -package:monoidal-containers -package:invertible -package:os-string is:exact package:pipes

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

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