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#212: Added sh:ShapeClass #254

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5224879
#212: Added sh:ShapeClass
HolgerKnublauch Feb 16, 2025
4600436
#212: Removed "meta" (class) as suggested by Andy
HolgerKnublauch Feb 18, 2025
d6e70f5
Merge branch 'gh-pages' into issue-212-ShapeClass
HolgerKnublauch Feb 18, 2025
e4758a5
#212: Added sh:ShapeClass to section heading
HolgerKnublauch Feb 18, 2025
544e336
Update shacl12-core/index.html
HolgerKnublauch Feb 25, 2025
b3fd3a7
Merge branch 'gh-pages' into issue-212-ShapeClass
HolgerKnublauch Feb 25, 2025
8daf6ee
#212: Made sh:ShapeClass a rdfs:Class and removed the sentence about it
HolgerKnublauch Feb 26, 2025
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26 changes: 25 additions & 1 deletion shacl12-core/index.html
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Expand Up @@ -1157,6 +1157,16 @@ <h4>Implicit Class Targets</h4>
in a <a>shapes graph</a> <code>SG</code> and <code>s</code> is also a <a>SHACL instance</a> of <code>rdfs:Class</code>
in <code>SG</code> then the set of <a>SHACL instances</a> of <code>s</code> in a data graph <code>DG</code> is a <a>target</a> from <code>DG</code> for <code>s</code> in <code>SG</code>.
</div>
<p id="ShapeClass">
The SHACL namespace includes a dedicated metaclass <code>sh:ShapeClass</code> that can serve as a syntactic shortcut for the implicit class targets pattern.
</p>
<div class="def">
<div class="def-header">TEXTUAL DEFINITION</div>
The class <code>sh:ShapeClass</code> is an <code>rdfs:subClassOf</code> of both <code>sh:NodeShape</code> and <code>rdfs:Class</code>.
<code>sh:ShapeClass</code> has itself as its <code>rdf:type</code>.
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This is not true.

sh:ShapeClass rdfs:subClassOf rdfs:Class , sh:NodeShape. # true
sh:ShapeClass a rdfs:Class. # true
sh:ShapeClass a sh:NodeShape. # FALSE!

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But the triple sh:ShapeClass rdf:type sh:ShapeClass is explicitly stated in the TTL file:

https://github.com/w3c/data-shapes/pull/254/files#diff-e7ad12ee6ccf9c41e835d5d12955c739ac6ead85384719f9a3cd0127f7a1c5fdR58

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@afs afs Feb 25, 2025 •
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In the textual definition, the sentence

sh:ShapeClass has itself as its rdf:type.

has two readings: as part of the definition and being an authoritative statement, or as stating a consequence of the first part. Replace the preceeding . with ; and it does make it part of the definition.

The class sh:ShapeClass is an rdfs:subClassOf of both sh:NodeShape and of rdfs:Class; sh:ShapeClass has itself as an rdf:type.

("an rdf:type" - it has unrelated ones as well)

The current 3rd sentence, which is definitely not adding to the definition, and is stating a consequence of "SHACL instance":

If s is a SHACL instance of sh:ShapeClass in a shapes graph SG then the set of SHACL instances of s in a data graph DG is a target from DG for s in SG.

could be moved to after the textual definition box so the definition box is all definition.

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Why should sh:ShapeClass rdf:type sh:ShapeClass be true?

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As I read it - because the definition says it is.

If it is the other reading where sh:ShapeClass rdf:type sh:ShapeClass is an implication, it does not need to be in the definition box. I don't see the implication path that concludes that fact but maybe I've missed it.

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Ok, what about I just remove that sentence? We do not make these assertions explicit in the spec of other things (e.g. we don't say that sh:NodeShape rdf:type rdfs:Class. This information is present in the sh: namespace TTL and that's probably good enough?

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I have removed the offending sentence and made sh:ShapeClass a rdfs:Class in the TTL file as this was not really necessary. I hope this addresses the concern here and will ask for another review

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@HolgerKnublauch --

Are you saying it is a natural conclusion from the rest of SHACL? What path leads to that?

If on the other hand, it is a necessary additional requirement about sh:ShapeClass then it should be in the definition. (i.e the definition should be complete and self-contained without the namespace document.)

Concretely - what requires sh:ShapeClass rdf:type sh:ShapeClass to work?

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what requires sh:ShapeClass rdf:type sh:ShapeClass to work?

Nothing really, so I have taken it out and made it rdfs:Class only. Maybe our messages crossed paths.

If <code>s</code> is a <a>SHACL instance</a> of <code>sh:ShapeClass</code> in a <a>shapes graph</a> <code>SG</code>
then the set of <a>SHACL instances</a> of <code>s</code> in a data graph <code>DG</code> is a <a>target</a> from <code>DG</code> for <code>s</code> in <code>SG</code>.
</div>
<p><em>The remainder of this section is informative.</em></p>
<p>
In the following example, <code>ex:Alice</code> is a focus node, because it is a <a>SHACL instance</a> of
Expand All @@ -1168,6 +1178,13 @@ <h4>Implicit Class Targets</h4>
<pre class="example-data">
<span class="focus-node-selected">ex:Alice</span> a ex:Person .
ex:NewYork a ex:Place .</pre>
<p>
In the following variation of the example above, <code>ex:Person</code> is declared as an instance of <code>sh:ShapeClass</code>,
with the same interpretation.
</p>
<pre class="example-shapes">
ex:Person
<b>a sh:ShapeClass</b> .</pre>
</section>

<section id="targetSubjectsOf">
Expand Down Expand Up @@ -4474,12 +4491,19 @@ <h2>Acknowledgements</h2>
<section class="appendix informative">
<h2>Revision History</h2>
<p>
The detailed list of changes and their diffs can be found in the Git repository.
The detailed list of changes and their diffs can be found in the <a href="https://github.com/w3c/data-shapes">Git repository</a>.
</p>
<ul>
<li><b>2024-02-14</b>: New work started by cloning the main SHACL spec and splitting it into SHACL Core and SHACL-SPARQL</li>
</ul>
</section>

<section class="appendix informative" id="changes-12">
<h2>Changes between SHACL 1.0 Core and SHACL 1.2 Core</h2>
<ul>
<li>Added the new metaclass <a href="#ShapeClass"><code>sh:ShapeClass</code></a> as syntactic sugar for implicit class targets, see <a href="https://github.com/w3c/data-shapes/issues/212">Issue 212</a></li>
</ul>
</section>

</body>

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1 change: 1 addition & 0 deletions shacl12-test-suite/tests/core/targets/manifest.ttl
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Expand Up @@ -8,6 +8,7 @@
mf:include <multipleTargets-001.ttl> ;
mf:include <targetClass-001.ttl> ;
mf:include <targetClassImplicit-001.ttl> ;
mf:include <targetClassImplicit-002.ttl> ;
mf:include <targetNode-001.ttl> ;
mf:include <targetObjectsOf-001.ttl> ;
mf:include <targetSubjectsOf-001.ttl> ;
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57 changes: 57 additions & 0 deletions shacl12-test-suite/tests/core/targets/targetClassImplicit-002.ttl
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@@ -0,0 +1,57 @@
@prefix dash: <http://datashapes.org/dash#> .
@prefix ex: <http://datashapes.org/sh/tests/core/targets/targetClassImplicit-002.test#> .
@prefix mf: <http://www.w3.org/2001/sw/DataAccess/tests/test-manifest#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix sht: <http://www.w3.org/ns/shacl-test#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

ex:InvalidInstance
rdf:type ex:SubClass ;
rdfs:label "Invalid instance" ;
.
ex:SubClass
rdf:type rdfs:Class ;
rdfs:label "Sub class" ;
rdfs:subClassOf ex:SuperClass ;
.
ex:SuperClass
a sh:ShapeClass ;
rdfs:label "Super class" ;
sh:in (
ex:ValidInstance
) ;
.
ex:ValidInstance
rdf:type ex:SubClass ;
rdfs:label "Valid instance" ;
.
<>
rdf:type mf:Manifest ;
mf:entries (
<targetClassImplicit-002>
) ;
.
<targetClassImplicit-002>
rdf:type sht:Validate ;
rdfs:label "Verify that sh:ShapeClass is interpreted as implicit class target" ;
mf:action [
sht:dataGraph <> ;
sht:shapesGraph <> ;
] ;
mf:result [
rdf:type sh:ValidationReport ;
sh:conforms "false"^^xsd:boolean ;
sh:result [
rdf:type sh:ValidationResult ;
sh:focusNode ex:InvalidInstance ;
sh:resultSeverity sh:Violation ;
sh:sourceConstraintComponent sh:InConstraintComponent ;
sh:sourceShape ex:SuperClass ;
sh:value ex:InvalidInstance ;
] ;
] ;
mf:status sht:approved ;
.
7 changes: 7 additions & 0 deletions shacl12-vocabularies/shacl.ttl
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Expand Up @@ -54,6 +54,13 @@ sh:PropertyShape
rdfs:subClassOf sh:Shape ;
rdfs:isDefinedBy sh: .

sh:ShapeClass
a sh:ShapeClass ;
rdfs:comment "A shape class is a class that is also a node shape. sh:ShapeClass can be used as rdf:type instead of the combination of rdfs:Class and sh:NodeShape."@en ;
rdfs:label "Shape class"@en ;
rdfs:subClassOf rdfs:Class ;
rdfs:subClassOf sh:NodeShape .

sh:deactivated
a rdf:Property ;
rdfs:label "deactivated"@en ;
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