forall and class contexts

Andrew J Bromage ajb@spamcop.net
Wed, 16 Oct 2002 17:45:05 +1000


G'day all.

On Wed, Oct 16, 2002 at 08:40:18AM +0100, Simon Peyton-Jones wrote:

> There aren't many type constructors T for which T a is an equality
> type...

I can think of a few, like IORef.  Admittedly I can't think of any that
are also monads.

Cheers,
Andrew Bromage