Re: [Haskell-cafe] Playing with ATs again

5 Aug 2010

      On Tue, Aug 3, 2010 at 9:45 PM, Ryan Ingram  wrote:
...
So I believe the "final" way to do this, which is not yet implemented,
works something like this:
type family LeftToRight a
type family RightToLeft b
class (LeftToRight a ~ b, RightToLeft b ~ a) => Bijection a b where
  ...
I agree, the fact that this doesn't work is really dumb.
I think it is more simple like:

class Bijection a b where
  ...

type LeftToRight a = (Bijection a b) => b
type RightToLeft b = (Bijection a b) => a

-- 
Victor Nazarov