[m-dev.] for review: add support for existential types [3/4]

[Fergus Henderson]

On 07-Jul-1998, David Glen JEFFERY <dgj at cs.mu.OZ.AU> wrote:
> > > > +	% XXX we should check that `TVars' is of the
> > > > +	%     appropriate form (i.e. a list of variables)
> > > 
> > > Does this get checked elsewhere?
> > 
> > No.
> > 
> > > If not, you should fix the code.
> > 
> > Yes, you are right <sigh>.
> 
> Can we see the diff for that bit?

Yes -- but not until I've written it! ;-)

> > +		% (XXX is this check overly conservative? Perhaps we should
> > +		% allow existential constraints so long as they contain
> > +		% at least one type variable which is existentially quantified,
> > +		% rather than requiring all variables in them to be
> > +		% existentially quantified.)
> 
> We need to think about this some more. What did we decide the other day when
> we talked about this?

We decided to go with the "Perhaps ..." above.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>  |  of excellence is a lethal habit"
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