rank-2 vs. arbitrary rank types

[Neil Mitchell]

Hi

> I guess another important point is to make sure that when we pick a
> design, then we have at least one (current) implementation that
> supports it (ideally, all implementations would eventually).  Could we
> get a heads up from implementors about the the current status and
> future plans in this area of the type checker?

To add something as simple as pattern guards to the Yhc/nhc type
checker is likely to require rewriting the type checker from scratch.
To add rank-N types would also require rewriting the checker from
scratch. I guess that means the Yhc team will have to find someone who
really wants to write a type checker...

Thanks

Neil