- From: Karen Coyle <kcoyle@kcoyle.net>
- Date: Sat, 04 Apr 2015 09:58:20 -0700
- To: Irene Polikoff <irene@topquadrant.com>
- CC: "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
No, that is unrelated to my comment. kc On 4/4/15 9:37 AM, Irene Polikoff wrote: > 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 >> > -- 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 16:58:52 UTC