[m-rev.] for review: comparison of preds/funcs

[Mark Brown]

On 13-Apr-2002, Zoltan Somogyi <zs at cs.mu.OZ.AU> wrote:
> On 13-Apr-2002, Mark Brown <dougl at cs.mu.OZ.AU> wrote:
> > This was the approach I tried first.  The problem is that the generic
> > routines can call the type specific routines in the type_ctor_infos.
> 
> But they don't do so when MR_COMPARE_BY_RTTI is enabled. The reason why
> we don't enable it for unify and compare is that those predicates can throw
> exceptions, which we do not handle properly across the C/Mercury interface.
> However, the new compare_representations predicate will not throw exceptions.
> Therefore enabling MR_COMPARE_BY_RTTI for it should work.
> 

Well, MR_COMPARE_BY_RTTI is undocumented, and enabling it results in a
compilation error.  I can address both of these issues if you like.  But
another problem is that, even with MR_COMPARE_BY_RTTI enabled, comparison
is still done through the type_ctor_info for arrays, so comparing by RTTI
will need to be implemented for arrays.  Is there a technical reason why
this hasn't been done yet, or is it just a case of "not yet implemented"?

Cheers,
Mark.

--------------------------------------------------------------------------
mercury-reviews mailing list
post:  mercury-reviews at cs.mu.oz.au
administrative address: owner-mercury-reviews at cs.mu.oz.au
unsubscribe: Address: mercury-reviews-request at cs.mu.oz.au Message: unsubscribe
subscribe:   Address: mercury-reviews-request at cs.mu.oz.au Message: subscribe
--------------------------------------------------------------------------