map is:exact -package:text -package:case-insensitive -package:base -package:Cabal-syntax -package:base-prelude -package:dense-linear-algebra -package:basement -package:monoidal-containers -package:hedgehog -package:aeson -package:amazonka-core package:pipes

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

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