@mcc @typeswitch there's a meme in Haskell, "it's always `traverse`", because `traverse :: (Traversable t, Applicative f) => (a -> f b) -> t a -> f (t b)` is useful for a lot of different things with the right choices of `f` and `t`. (in this case `f = IO`, `t = List`, and `for_ xs f = void (traverse f xs)`)