Re: [Haskell-beginners] deducing type of multi-parameter type class

On Thu, Jul 15, 2010 at 10:09 AM, Felipe Lessa wrote:

On Thu, Jul 15, 2010 at 3:13 AM, Michael Snoyman wrote:

...

You could also use type families for this, but I believe you cannot express the "Show" superclass: class MyClass a where type MyResult a fn :: a -> MyResult a

I guess this works:

class Show (MyResult a) => MyClass a where type MyResult a fn :: a -> MyResult a

Thanks, I forgot about that. Funny, because I use it in Yesod ;). Michael