Vec3.hs

data Vec3 a = Vec3 a a a deriving (Eq, Show)

instance Functor Vec3 where
  fmap f (Vec3 a b c) = Vec3 (f a) (f b) (f c)

instance Applicative Vec3 where
  pure a = Vec3 a a a
  (Vec3 f f' f'') <*> (Vec3 a b c)  =  Vec3 (f a) (f' b) (f'' c)

instance Foldable Vec3 where
   foldr :: (a -> b -> b) -> b -> Vec3 a -> b
   foldr f d (Vec3 a b c) = f a (f b (f c d))

instance Traversable Vec3 where
  traverse :: Applicative f => (a -> f b) -> Vec3 a -> f (Vec3 b)
  traverse f (Vec3 a b c) = Vec3 <$> f a <*> f b <*> f c