[m-dev.] polymorphic modes

[David Overton]

On Wed, 09 Feb, 2000 at 02:03:21PM EST, Fergus Henderson wrote:
> On 09-Feb-2000, David Overton <dmo at ender.cs.mu.oz.au> wrote:
> > What I have currently done is assume that all inst parameters in
> > predicate and function mode declarations are implicitly constrained to
> > be ground(shared).  E.g.
> > 
> > 	:- mode p(in(I), out(I)).
> > 
> > works for all insts, I, that are ground(shared), such as:
> > 
> > 	:- mode p(in(ground), out(ground)).
> > 	:- mode p(in(pred(in, in) is semidet), out(pred(in, in) is semidet)).
> > 	:- mode p(in(bound(foo)), out(bound(foo))).
> > 
> > However, unique insts are not allowed to match inst parameters, so
> > 	
> > 	:- mode p(in(unique), out(unique)).
> > 
> > is not an instance of the polymorphic mode.
> 
> What happens if you call p/1 with a arguments whose
> initial insts are `(unique, free)'?  Does that end
> up calling the `p(in(ground), out(ground))' mode,
> or is it a mode error?
> 

The former.

-- 
David Overton       Department of Computer Science & Software Engineering
PhD Student         The University of Melbourne, Australia
+61 3 9344 9159     http://www.cs.mu.oz.au/~dmo
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