Re: [Haskell-cafe] Modulo-foo equivalence classes in Haskell?

newtype Y = Y { unY :: X }

instance Eq Y where (==) = foo

nub' :: [X] -> [X] nub' = map unY . sort . map Y

Yes, I thought of that. I'm really thinking of how I can generalize the Eq class so I dont have to go around manually "lifting" operations that are already defined (like operations on integers for modulo-n rings) -- Diego Navarro