On Wed, Jan 13, 2010 at 2:14 PM, Bulat Ziganshin <bulat.ziganshin@gmail.com> wrote:

class Open a where
open :: a

instance Open (Int -> String) where ...
instance Open (String -> Int) where ...

The problem with this approach is that you'll need to supply type annotations with basically every use of open, which is even more verbose than prepending the type name.

-Edward Kmett