map -package:containers -package:imports -package:blaze-html -package:dense-linear-algebra -package:amazonka-core -package:Cabal-syntax -package:invertible is:exact -package:hedgehog -package:charset -package:insert-ordered-containers -package:bytestring package:pipes

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

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