- From: Holger Knublauch <holger@topquadrant.com>
- Date: Thu, 7 Apr 2016 15:01:33 +1000
- To: public-data-shapes-wg@w3.org
- Message-ID: <5705E9AD.2050803@topquadrant.com>
See http://w3c.github.io/data-shapes/shacl/#shapes-graph-invalid The classes|sh:NodeConstraint|,|sh:PropertyConstraint|and|sh:InversePropertyConstraint|are pairwise disjoint HTH Holger On 7/04/2016 14:43, Karen Coyle wrote: > Thanks, Holger. But can you say exactly which classes will be defined > as disjoint from each other? I'm still finding this rather vague. Or > maybe it's in the issue somewhere? > > kc > > On 4/6/16 7:27 PM, Holger Knublauch wrote: >> Karen, >> >> I don't think you need to be concerned. This is merely about corner >> cases such as >> >> ex:MyShape >> a sh:Shape ; >> sh:property ex:c ; >> sh:inverseProperty ex:c . >> >> ex:c a sh:PropertyConstraint ; >> sh:predicate .... >> >> i.e. a constraint node is shared as both sh:property and >> sh:inverseProperty. I don't think anybody would practically do this, but >> we need to exclude that possibility to help the engine decide which >> SPARQL to run. >> >> It does not make the use of, say, sh:minCount and sh:class disjoint with >> each other. >> >> HTH >> Holger >> >> >> On 7/04/2016 12:22, Karen Coyle wrote: >>> 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 >>>>> >>>> >>> >> >> >> >
Received on Thursday, 7 April 2016 05:02:07 UTC