Re: shapes-ISSUE-168 (instance count): How to constrain number of instances of a class in a graph [SHACL - Core]

Interesting. Can you point out where this is explained in the spec? - kc

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 Friday, 17 June 2016 18:48:26 UTC