Hello Martin, Friday, March 23, 2007, 11:37:16 PM, you wrote:
>> readValue' :: Field -> Maybe (forall s. SqlBind s => s) -> Value > Thank you very much, that's exactly what I wanted. After reading in the > GHC users guide about rank 2 polymorphism I thought that this is not > possible. Chapter "7.4.8. Arbitrary-rank polymorphism" says: "impredicative polymorphism" is new in ghc 6.6. look for this word in ghc docs and in spj's papers -- Best regards, Bulat mailto:[EMAIL PROTECTED] _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
