map -package:containers -package:insert-ordered-containers -package:amazonka-core -package:dense-linear-algebra is:exact -package:blaze-html -package:monoidal-containers -package:imports -package:base -package:os-string -package:incipit-base package:pipes

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

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