Re: [RIF] test case dialect indicators

If a rule is syntactically correct PRD and syntactically correct Core and 
non-terminating in PRD, then why is it OK to have it in PRD but not in 
core - this is what I don't understand. Is it that you want to make sure 
there can be conformant PRD  implementations of Core but you do not need 
to ensure that there can be conformant implementations of PRD?

Stella





Dave Reynolds <der@hplb.hpl.hp.com> 
Sent by: public-rif-wg-request@w3.org
11/14/2008 04:27 AM

To
Stella Mitchell/Watson/IBM@IBMUS
cc
"Boley, Harold" <Harold.Boley@nrc-cnrc.gc.ca>, RIF WG 
<public-rif-wg@w3.org>
Subject
Re: [RIF] test case dialect indicators







Stella Mitchell wrote:
> 
> Ok, so it looks like for test cases that are core, we should indicate 
> also whether they are safe or not.

Yes.

> One thing that wasn't clear to me (from the Core document) is whether 
> PRD extends core or safe-core.  The last paragraph of the overview says 
> core is a syntactic subset of PRD but that some core rules would be 
> unsafe in PRD, so safe-core is defined. But if complete-core is a 
> syntactic subset of PRD then those unsafe rules must be allowed 
> according to the PRD spec anyway, so why define the safe subset of core?

Because then we could write test cases which were correct RIF-Core but 
which no RIF-PRD engine could pass (e.g. because the ruleset would never 
terminate) even though the rules would be syntactically legal RIF-PRD.

One goal for RIF-Core is for it be as widely implementable as possible. 
Having test cases which no production rule engine would pass would mean 
there would be no conformant PR implementation of RIF-Core.

The advice to people wishing to exchange rules via RIF-Core is to remain 
within the safe subset to get maximal interchange however we don't 
prevent people exchanging unsafe rules.

Dave
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