On Mon, Jul 20, 2009 at 05:46:14PM -0300, Maurício wrote:
data (Eq a) => Object a = Object a
I'd rewrite this as newtype Object a = Object a
instance (Named a) => Eq a where (==) = equals
Be careful with this instance! (specially since this is haskell-beginners)
instance Named (Object Integer) where type NameType (Object Integer) = Integer name (Object i) = i
I'd rewrite this as instance Eq a => Named (Object a) where type NameType (Object a) = a name (Object a) = a instance Eq a => Eq (Object a) where (==) = equals However, I guess something like data Name n a = Name n a instance Functor (Name n) where fmap f (Name n a) = Name n (f a) instance Eq n => Named (Name n a) where type NameType (Name n a) = n name (Name n _) = n instance Copointed (Name n) where -- from category-extras extract (Name _ a) = a would be a whole lot more useful, no? -- Felipe.