Type class problem

Simon Peyton-Jones simonpj@microsoft.com
Tue, 2 Sep 2003 08:02:28 +0100


| I'm wondering if the general method of avoiding non-termination can be
| made to work in these more complex cases.
|=20
| Incidentally, the constraint solver stack overflow problem can be
| turned to our advantage. The typechecker's exhausting the stack should
| be considered a failure to match the instance -- and so the
| typechecker should mark the current instance inappropriate and try
| another one, if any.

Ultimately, this boils down to solving the halting problem, I believe.
Stack-overflow isn't a proof that the thing isn't soluble.  I can
believe that it woks nicely in practice, but it's a bit of a hack!

Simon