Hello Brian, Thursday, September 14, 2006, 7:43:55 PM, you wrote:
> Even if the compiler did know, by some other means, that a Node had been > wrapped, Haskell doesn't support true existentials > whereas you'd really need an existential: > getCommon :: (forall gc. Node gc) -> Common they are supported in ghc 6.6 with name of "impredicative polymorphism", section 7.4.9 or 7.4.10 of new user manual -- Best regards, Bulat mailto:[EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
