3 ms·
It's this contramap :: (a -> b) -> f b -> f a http://hackage.haskell.org/package/contravariant-1.3.3/docs/Data-Functor-Contravariant.html#v:contramap
by boothead 11y ago
It's this
contramap :: (a -> b) -> f b -> f a
http://hackage.haskell.org/package/contravariant-1.3.3/docs/Data-Functor-Contravariant.html#v:contramap
- pka 11y agoI thought "Extension" in this example is a Monoid. So maybe foldContramap? :)