Re: [Haskell-cafe] Newbie question about tuples

On Thu, 12 Jul 2007, Andrew Coppin wrote:

peterv wrote:

...

Q3) Suppose I want to declare an instance of Num on all tuple types having (Num instances) as elements; is this possible?

I tried

instance Num a => Num (a,a) where .

but this fails

I also tried

instance Num a => Num ((,) a a) where .

but that also fails.

I tried to do this a while ago and couldn't figure out how. :-(

The new approach of peterv using data Vector2 a = Vector2 a a is more sane.