> 
> import IO
> 
> class Foo a where
>   bar :: a -> [a]
> 
> instance Foo Int where
>   bar x = replicate x x
> 
> data Record = R {
>      blub :: Foo a => a -> [a]
>     }
> 
> main = do
>   let r = R {blub = bar}
> 
>   --print (bar (3::Int)) -- works!
>   print ((blub r) (3::Int)) -- fails!