Re: difference between sh:hasValue and sh:in

It is possible for different RDF graphs to share blank nodes.   Indeed SHACL
depends on this facility.  As well, as Dimitris points out SHACL permits the
data graph and the shapes graph to be the same.

I think that this ends up with cases where it can be useful for the value of
sh:targetNode, sh:targetClass, and sh:class to be a blank node.  I don't think
that there are any other parameters that currently exclude IRIs but where IRIs
are useful.

peter

PS:  Here is an example of a blank node class in a shape.

Data/shapes graph:

ex:s1 rdf:type sh:Shape ;
  sh:targetClass _:c1 ;
  sh:nodeKind sh:IRI .

ex:i1 rdf:type _:c1 .
_:i2 rdf:type _:c1 .

PPS:  Issues should be raised for changes to SHACL like this, as disposing of
the issue lets the working group think about the scope of the change.


On 12/11/2016 11:21 PM, Dimitris Kontokostas wrote:
> Allowing bnodes would always fail validation when the data graph and the
> shapes graph are not the same but I do not see any other problem.
> Since it does not affect the language I suggest we allow it for both, someone
> might find a use case for this
> 
> 
> On Mon, Dec 12, 2016 at 2:06 AM, Holger Knublauch <holger@topquadrant.com
> <mailto:holger@topquadrant.com>> wrote:
> 
>     What would you suggest:
>     a) disallow bnodes for both
>     b) allow bnodes for both.
> 
>     I have no strong opinion on this. Does anyone have use cases for bnodes in
>     sh:hasValue?
> 
>     Holger
> 
> 
> 
>     On 12/12/2016 7:34, Peter F. Patel-Schneider wrote:
> 
>         sh:hasValue allows blank nodes but sh:in does not.
> 
> 
>         This difference does not seem to have any rationale.  If blank nodes are
>         allowed for sh:hasValue then they should be allowed for sh:in.
> 
> 
> 
>         Peter F. Patel-Schneider
>         Nuance Communications
> 
> 
> 
> 
> 
> 
> -- 
> Dimitris Kontokostas
> Department of Computer Science, University of Leipzig & DBpedia Association
> Projects: http://dbpedia.org, http://rdfunit.aksw.org, http://aligned-project.eu
> Homepage: http://aksw.org/DimitrisKontokostas
> Research Group: AKSW/KILT http://aksw.org/Groups/KILT
>

Received on Monday, 12 December 2016 19:13:13 UTC