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Re: More wording

From: Irene Polikoff <irene@topquadrant.com>
Date: Mon, 18 Apr 2016 15:15:39 -0600
Message-Id: <FD385F46-187F-4F69-94DB-6E708049655C@topquadrant.com>
Cc: "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
To: kcoyle@kcoyle.net
The 'groups' language only works given the context. It wouldn't work in a more general sense. One would not say that a Person groups names - this doesn't make sense, but one may say that a Family groups family members or People.

In any case, Karen's proposed language works for me.

Sent from my iPhone

> On Apr 18, 2016, at 2:11 PM, Karen Coyle <kcoyle@kcoyle.net> wrote:
> 
> OK, thanks, Peter. That truly wasn't clear, so I'll read further to see if this definition is followed in the text.
> 
> But as an example, to me, the definition does not fit with the statement: "SHACL groups descriptive information and constraints that apply to a given data node into shapes. This document defines what it means for an RDF graph, referred to as the "data graph", to conform to a graph containing SHACL shapes, referred to as the "shapes graph"."
> 
> I have trouble with "groups ... constraints ... into shapes" if a shape is an IRI/bnode. That is what made me think that shapes were intended to be graphs, not things (graphs being groups of 1 or more triples). (You wouldn't say: "groups names into Persons".) Perhaps:
> 
> "A shape is an instance of the class sh:Shape, either an IRI or a blank node. The descriptive information and constraints that apply to a given data node are defined as the properties of a shape. A set of shapes that defines validation rules for a data graph (?or a portion of a data graph?) is called a 'shapes graph'. A shapes graph consists of one or more shapes."
> 
> Closer?
> 
> kc
> 
>> On 4/18/16 9:40 AM, Peter F. Patel-Schneider wrote:
>> There may be some misunderstanding here.  Shapes in SHACL are IRIs or blank
>> nodes and come from RDF graphs that are to be considered as shapes graphs.
>> RDF graphs are generally not considered to be instances of classes.
>> 
>> SHACL documents should be clear that SHACL shapes are IRIs or blank nodes
>> and not graphs or sets of triples.
>> 
>> 
>> 
>> Here is some Turtle syntax for an RDF graph
>> 
>> @prefix ex: <http://example.com/> .
>> @prefix ex: <http://www.w3.org/ns/shacl#> .
>> 
>> ex:s1 a sh:Shape ;
>>   sh:scopeClass ex:Person ;
>>   ex:property [ a sh:PropertyConstraint ;
>>              ex:predicate ex:p1 ;
>>                 ex:valueShape ex:s2 ] ;
>>   ex:constraint [ a sh:PropertyConstraint ;
>>                   ex:predicate ex:p2 ;
>>          ex:valueShape [ a sh:Shape ;
>>                    ex:constraint [ a sh:NodeConstraint ;
>>                                          sh:class ex:Student ] ] ] .
>> ex:s2 a sh:Shape ;
>>   sh:constraint [ a sh:NodeConstraint ;
>>             sh:nodeKind sh:IRI ] .
>> 
>> When treated as a shapes graph, an RDF graph that results from this Turtle
>> syntax has three shapes in it
>> 1. http://example.com/s1
>> 2. http://example.com/s2
>> 3. the blank node that is allocated when matching
>>       [ a sh:Shape ;
>>      ex:constraint [ a sh:NodeConstraint ;
>>                sh:class ex:Student ] ]
>> 
>> peter
>> 
>> 
>>> On 04/18/2016 09:03 AM, Karen Coyle wrote:
>>> 2. Shapes
>>> 
>>> Is: "Shapes are instances of the class sh:Shape and define a group of
>>> constraints that a set of focus nodes can be validated against."
>>> 
>>> Suggest: "Shapes are graphs that are instances of the the class sh:Shape.
>>> Shapes define one or more focus nodes in a data graph and constraints on
>>> triples in those focus nodes. The triples in the focus nodes are validated
>>> against the constraints in the shape."
>>> 
>>> I also suggest that we define "shape" as "an RDF graph of type sh:Shape" and
>>> not use "shape graph" but always use "shape" since "shape graph" is redundant.
>>> 
>>> I can make this change if we have agreement on it. If I don't hear back I may
>>> make this definition an issue.
>>> 
>>> kc
> 
> -- 
> Karen Coyle
> kcoyle@kcoyle.net http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet/+1-510-984-3600
> 
Received on Monday, 18 April 2016 21:16:15 UTC

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