Hello Ross, Thursday, September 21, 2006, 12:55:40 PM, you wrote:
>> data Ex = forall a. Num a => Ex a >> >> and >> >> data Po = Po (forall a. Num a => a) > Consider the types of the constructors: > Ex :: forall a. (Num a) => a -> Ex > Po :: (forall a. (Num a) => a) -> Po sorry, Ross, can you give me a more detailed explanation? it seems that Po argument is existential by itself, but i don't understand that all this mean also, ghc66 adds impredicative polymorphism. how it differs from unqualified existentials? -- Best regards, Bulat mailto:[EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
