[Haskell-cafe] More experiments with ATs

[Sjoerd Visscher]

On Jul 4, 2010, at 1:58 PM, Steffen Schuldenzucker wrote:

> This works (on my ghc-6.12.2):
> 
>> class Rfunctor f where
>>    type F f :: * -> *
>>    (%) :: f a b -> (a -> b) -> F f a -> F f b

Yes, but then this isn't allowed:

data BSFunctor :: * -> * -> * where
  BS :: BSFunctor Word8 Word8
instance RFunctor BSFunctor where
  type F BSFunctor Word8 = B.ByteString
  BS % f = B.map f

--
Sjoerd Visscher