-- | A prism which focuses on the right branch of an Either
_Right :: Prism (Either x a) (Either x b) a b
_Right = rmap (either (pure . Left) (Right <$>)) . right'
_Right :: Prism (Either x a) (Either x b) a b
_Right = rmap (either (pure . Left) (Right <$>)) . right'
_Right = rmap (either (pure . Left) (Right <$>)) . right'