3 Mar
2007
3 Mar
'07
2:01 p.m.
On 03/03/07, C Rodrigues
class Foo a b | a -> b where foo :: a -> FooBox b data FooBox b = forall c. Foo b c => FooBox (Maybe c)
Existential boxes is indeed the method I've used to tackle this in practice. However, it's kind of annoying, hence my email asking whether there's a good reason it's not possible. I guess there are no theoretical limitations, because, as you've just shown, you can hack your way around it. -- -David House, dmhouse@gmail.com