Re: shapes-ISSUE-91 (hsolbrig): Default Cardinality [SHACL Spec]

I think that the cardinality defaults interact with the closed/open 
graph definition. If the graph is open, then a default of 
"minCardinality = 0, maxCardinality = *" is pretty close to meaningless. 
In an open graph, all potential predicates are "optional" unless defined 
otherwise, and specifying optional predicates does not invoke any useful 
behavior. In the case of an closed graph, "minCardinality = 0" describes 
a specific optional predicate.

SHACL, if I understand it correctly, describes an open graph by default. 
This means that only ""minCardinality > 0" can be validated.

Although the statement by Holger that "if something is left unspecified 
then it should count as unconstrained" resonates, I would consider the 
inclusion of a optional property to be specified, not unspecified.


On 9/25/15 1:02 AM, Holger Knublauch wrote:
> I believe if something is left unspecified then it should count as
> unconstrained. So if no sh:minCount or sh:maxCount is given then it
> should count as 0..* by default.
> PROPOSAL: Close ISSUE-91 stating that the default interpretations of
> sh:minCount and sh:maxCount (and their qualified counterparts) should
> remain as currently specified.
> Holger
> PS: A compact syntax may of course use different conventions and
> automatically generate the corresponding min/max triples.
> On 9/25/2015 0:46, RDF Data Shapes Working Group Issue Tracker wrote:
>> shapes-ISSUE-91 (hsolbrig): Default Cardinality [SHACL Spec]
>> Raised by: Harold Solbrig
>> On product: SHACL Spec
>> The defaults for cardinality in UML are [1..1]  (see:
>> MultiplicityElement.lowerBound() and MultiplicityElement.upperBound()
>> on page 41 of OMG specification ptc/2013-09-05).  Should these be the
>> defaults for mincount and maxcount in Section 3.1.5 of the SHACL
>> specification as well?  Currently they are [0..*].

Karen Coyle
m: 1-510-435-8234
skype: kcoylenet/+1-510-984-3600

Received on Friday, 25 September 2015 12:15:55 UTC