If you are willing to depend on a recent version of base where Num is no longer a subclass of Eq and Show, it is also fine to do this:
instance Num a => Num (r -> a) where
(f + g) x = f x + g x
fromInteger = const . fromInteger
and so on.
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
