Hi GHC users, I've been trying to create a instance for Maybe type in the Storable class. I need to override the peek and poke methods, but I'm having some difficulties. I was intended to do something like this: instance Storable t =>Storable (Maybe t) where peek ptr = maybePeek peek ptr poke ptr valMaybe = do ptr<-maybeNew (new) valMaybe return() Obviously, there is a type error on the definition of peek, because the type of prt is (Ptr a), not (Ptr (Maybe a)) . I don't know how to fix it and, at the same time, keep using instanciation. I would be grateful for suggestions, Regards, _________________________________________________ Nivia Cruz Quental Graduação em Eng. Computação - UPE Técnica em Telecomunicações - CEFET-PE - Brasil --------------------------------- Crie seu Yahoo! Mail, agora com 100MB de espaço, anti-spam e antivírus grátis!