Romildo, > I could write the (Functor ExprF) instance: > > instance Functor ExprF where > fmap f expr = case expr of > Num n -> Num n > Var v -> Var v > Bin op x y -> Bin op (f x) (f y)
Yes, excellent. That'll do. Cheers, Stefan _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
