Re: shapes-ISSUE-39 (Value shape facet): Naming of value shape facet [SHACL Spec]

Karen,

As I understand it, different predicates are proposed for describing what a value of a property should be. The best names for these predicates are still being discussed, so I am just calling these predicate 1, 2 and 3:

Predicate 1 allows one to say that values of a property must be members of a certain class.

For example, values of :nationality must be members of class :Country. This allows limiting the values to some RDF vocabulary.

Predicate 2 allows one to say that values of a property must be a literal or it must be an IRI or it must be a blank node.

Predicate 3 allows one to say that values of a property must comply with a specified shape. This is what 'valueShape' is about.

Could it be that you are wondering why three separate predicates are needed?

Irene


> On Apr 4, 2015, at 10:30 AM, Karen Coyle <kcoyle@kcoyle.net> wrote:
> 
> I wasn't able to answer this one because the property, as defined, doesn't make sense to me.
> 
> The definition in the document is: "The property sh:valueShape can be used verify that all values of the given property must match a given shape."
> 
> But in the introduction, there is a clear separation between node constraints and property contraints:
> 
> "A shape describes a group of local constraints with the same focus node. Many of these constraints are about a certain property only, and these are called property constraints."
> 
> To me, constraints on values are property constraints, while constraints on the content or shape of the node (e.g. the properties and classes) are shape constraints. Thus the statement "all values of a given property must match a given shape" would make more sense as "all values of a given property must match the property constraint".
> 
> "valueShape" reads to me as "appleOrange", and that section of the document isn't clear for this reason. Also, that section only shows a nested example. The text should make clear that the value can be a literal, a datatype, or a node, and should show how one indicates those. I am particularly interested in how one would create a constraint that limits the value to a particular literal list, and another example that shows limiting to a particular RDF-defined vocabulary.
> 
> kc
> 
>> On 4/2/15 4:21 PM, RDF Data Shapes Working Group Issue Tracker wrote:
>> shapes-ISSUE-39 (Value shape facet): Naming of value shape facet [SHACL Spec]
>> 
>> http://www.w3.org/2014/data-shapes/track/issues/39
>> 
>> Raised by: Holger Knublauch
>> On product: SHACL Spec
>> 
>> See https://www.w3.org/2014/data-shapes/wiki/Facet_Property_Names
>> 
>> How should the facet property for value shapes be called? Please cast your vote on the page linked above.
> 
> -- 
> Karen Coyle
> kcoyle@kcoyle.net http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet/+1-510-984-3600
>

Received on Saturday, 4 April 2015 16:37:57 UTC