Re: [Haskell-cafe] Confused about type seen in the wild

On Thu, Apr 10, 2014 at 9:27 AM, Albert Y. C. Lai wrote:

Yes, GHC accepts "X => Y => Z" and makes it "(X, Y) => Z". In fact, go

wilder:

whee :: Show a => Eq a => a => Bool whee x = x == x && null (show x)

It is valid and it means (Show a, Eq a) => a -> Bool. Try it!

What extensions do you have turned on? I'm trying this is ghci (7.6.3) and I can't get it to work even with DataKinds and ConstraintKinds. Jason