Open ghost opened 9 years ago
http://hackage.haskell.org/package/base-4.8.1.0/docs/Control-Applicative.html#t:Const
Bifunctor too!
Bifunctor
instance Bifunctor Const where bimap f _ (Const a) = Const (f a)
http://hackage.haskell.org/package/base-4.8.1.0/docs/Control-Applicative.html#t:Const