Re: Applicative-based definitions in Data.Foldable

I used `anyA` today, to run predicates on things contained in IORefs. On Fri, Dec 21, 2018 at 10:37 AM Isaac Elliott wrote:

With the introduction of the 'Ap' monoid in base-4.13, it seems like Applicative based definitions for common folds would be appropriate in base.

For example:

...

allA :: (Applicative f, Foldable t) => (a -> f Bool) -> t a -> f Bool allA f = fmap getAll . getAp . foldMap (Ap . fmap All . f)

...

all :: Foldable t => (a -> Bool) -> t a -> Bool all f = runIdentity . allA (Identity . f)

I've personally written the Applicative version in everyday code. Thoughts?

Isaac