[Haskell-cafe] Instancing "Typeable" for monad transformers?

[oleg at okmij.org]

One can do something a bit shorter

> instance (Typeable a, Typeable1 m) => Typeable1 (Iteratee a m) where
>   typeOf1 i = mkTyConApp (mkTyCon "Data.Enumerator.Iteratee") 
> 	            [typeOf a, typeOf1 m]
>    where
>    (a,m) = peel i
>    peel :: Iteratee a m w -> (a, m ())
>    peel = undefined


still a bother to write every time one needs it, but tolerable. Only
the signature of 'peel' matters.