- From: Karen Coyle <kcoyle@kcoyle.net>
- Date: Sat, 18 Jun 2016 05:16:52 -0700
- To: public-data-shapes-wg@w3.org
On 6/17/16 4:02 PM, Holger Knublauch wrote: > > On 18/06/2016 4:47, Karen Coyle wrote: >> Interesting. Can you point out where this is explained in the spec? - kc > > In the beginning of section 4, when you scroll down to the definition of > value nodes: This isn't much use to the person reading the definition of scopeNode in 2.1.1. Also, this particular solution applies to any node, not rdf:type nodes, and should be described as such. I'm still not clear how scopeNode applies to objects of a triple, unless it applies to any of s, p, o. Again, not clarified in the section. kc > > * For node constraints > <http://w3c.github.io/data-shapes/shacl/#dfn-node-constraints> the value > nodes are the individual focus nodes > <http://w3c.github.io/data-shapes/shacl/#dfn-focus-node>, forming a > set of exactly one node. > > The spec doesn't have to be written that way, and there are arguments in > favor of changing it so that it applies to > - either all scope nodes (when called from the top-level) > - or just the focus node (when called as nested shape, e.g. via > sh:shape, sh:or) > > Maybe we can resolve this next week too. > > Holger > > >> >> On 6/17/16 10:22 AM, Irene Polikoff wrote: >>> The way I understand it, when one uses scopeClass, the constraints apply >>> to each SHACL instance of a class individually. For example, each >>> instance >>> of a Person can have only two parents. And a condition is tested against >>> each node individually. >>> >>> This constraint, however, doesnąt apply to each instance >>> individually. It >>> is about the number of all instances. This is quite different, so I >>> wouldnąt expect to use scopeClass. >>> >>> Irene >>> >>> >>> >>> >>> >>> >>> On 6/17/16, 1:10 PM, "Karen Coyle" <kcoyle@kcoyle.net> wrote: >>> >>>> My preference overall would be to not use classes at all in validation; >>>> to have all operations on triples, and rdf:type would be simply a >>>> predicate like any other. (I believe that ShEx takes this approach.) >>>> However, if you encourage people to view the objects of rdf:type as >>>> classes, then you have to allow them to do so throughout, otherwise it >>>> becomes difficult to explain "when is a class not a class?". >>>> >>>> With the solution in this proposal, we have what to the user is a class >>>> but it does not use scopeClass, and scopeNode binds to the subject of a >>>> triple, AFAI can determine. The below would not match the schema.org >>>> example.[1] >>>> >>>> kc >>>> [1] http://schema.org/FlightReservation >>>> >>>> >>>> On 6/13/16 5:04 AM, RDF Data Shapes Working Group Issue Tracker wrote: >>>>> shapes-ISSUE-168 (instance count): How to constrain number of >>>>> instances >>>>> of a class in a graph [SHACL - Core] >>>>> >>>>> http://www.w3.org/2014/data-shapes/track/issues/168 >>>>> >>>>> Raised by: Holger Knublauch >>>>> On product: SHACL - Core >>>>> >>>>> There was recent discussion about how to specify min/max numbers of >>>>> instances in a graph. Off-list I had also received a question from >>>>> schema.org people about how to state that a graph/message must have >>>>> exactly one instance of schema:FlightReservation, possibly to ensure >>>>> that a graph has a starting point/root for validation. >>>>> >>>>> A possible syntax that would easily work with the current architecture >>>>> could be >>>>> >>>>> ex:MyShape >>>>> a sh:Shape ; >>>>> sh:scopeNode schema:FlightReservation ; >>>>> sh:constraint [ >>>>> sh:minInstanceCount 1 ; >>>>> sh:maxInstanceCount 1 ; >>>>> ] . >>>>> >>>>> >>>>> >>>>> >>>> >>>> -- >>>> Karen Coyle >>>> kcoyle@kcoyle.net http://kcoyle.net >>>> m: 1-510-435-8234 >>>> skype: kcoylenet/+1-510-984-3600 >>>> >>> >>> >>> >> > -- Karen Coyle kcoyle@kcoyle.net http://kcoyle.net m: 1-510-435-8234 skype: kcoylenet/+1-510-984-3600
Received on Saturday, 18 June 2016 12:17:22 UTC