W3C home > Mailing lists > Public > public-data-shapes-wg@w3.org > April 2016

Re: shapes-ISSUE-134 (knowing inverse): does SHACL syntax distinguish inverse property constraints [SHACL Spec]

From: Karen Coyle <kcoyle@kcoyle.net>
Date: Wed, 6 Apr 2016 19:22:14 -0700
To: public-data-shapes-wg@w3.org
Message-ID: <5705C456.7080403@kcoyle.net>
All WHAT disjoint? All constraints? That not only makes me nervous about 
unintended consequences, but in addition since we've rejected 
inferencing, I'm not sure what it does. If nothing else, pairwise 
disjoint rules on every possible combination of constraints could be 
burdensome if your software is expected to enforce that. And I'd like a 
run-through of the constraints to make sure this doesn't trip us up 
somewhere down the line. In general, my preference is to avoid declaring 
disjoint classes or properties except when absolutely necessary.

Could you give an example of the case that brought this up, and see if 
it generalizes to other constraint classes?

kc

On 4/6/16 12:57 AM, Holger Knublauch wrote:
> Yeah, why not. I just made them all disjoint. This is a rather
> theoretical corner case anyway, so being conservative here will make our
> lives easier:
>
> The
> classes|sh:NodeConstraint|,|sh:PropertyConstraint|and|sh:InversePropertyConstraint|are
> pairwise disjoint, i.e. it is illegal to have shape definitions that use
> nodes that are instances of two or more of these classes - either
> explicitly stated via|rdf:type|or implicitly via theirdefault value type.
>
> Thanks,
> Holger
>
>
> On 6/04/2016 17:42, Dimitris Kontokostas wrote:
>>
>> On Wed, Apr 6, 2016 at 10:08 AM, Holger Knublauch
>> <<mailto:holger@topquadrant.com>holger@topquadrant.com> wrote:
>>
>>     On 11/03/2016 15:57, Holger Knublauch wrote:
>>>     Ok, we can leave this ticket open here as a reminder that this
>>>     needs to be clarified. Like the other unwritten details about
>>>     sh:property vs sh:inverseProperty vs sh:constraint, this will be
>>>     cleaned up once we have resolved the general metamodel discussion.
>>
>>     I believe this ISSUE-134 can be closed now: Section 2.3 now
>>     includes a paragraph:
>>
>>     The
>>     classes|sh:PropertyConstraint|and|sh:InversePropertyConstraint|are
>>     disjoint, i.e. it is illegal to have shape definitions that use
>>     nodes that are instances of both classes - either explicitly
>>     stated via|rdf:type|or implicitly via theirdefault value type.
>>
>>
>> Can we say that all constraint types are pairwise disjoint?
>> we can get in similar cases when someone uses sh:NodeConstraint
>> and sh:InversePropertyConstraint
>> this means that constraint IRIs can be reused but only with same
>> constraint types
>> Dimitris
>>
>>
>>
>> --
>> Dimitris Kontokostas
>> Department of Computer Science, University of Leipzig & DBpedia
>> Association
>> Projects: <http://dbpedia.org>http://dbpedia.org,
>> http://rdfunit.aksw.org,
>> http://<http://aligned-project.eu/>http://aligned-project.eu
>> Homepage:<http://aksw.org/DimitrisKontokostas>http://aksw.org/DimitrisKontokostas
>> Research Group: AKSW/KILT http://aksw.org/Groups/KILT
>>
>

-- 
Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
m: 1-510-435-8234
skype: kcoylenet/+1-510-984-3600
Received on Thursday, 7 April 2016 02:21:53 UTC

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