David, Ryan Ingram wrote:
>>> Haskell doesn't have true type functions; what you are really saying >>> is >>> >>> instance Monad (\v -> Vect k (Monomial v)) Daniel Fischer wrote: > I think there was a theoretical reason why that isn't allowed (making type > inference undecidable? I don't remember, I don't recall ...). Indeed: type inference in the presence of type-level lambdas requires higher-order unification, which is undecidable [1]. Cheers, Stefan [1] Gérard P. Huet: The Undecidability of Unification in Third Order Logic Information and Control 22(3): 257-267 (1973) _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
