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#514: Renamed shnex:path to shnex:pathValues and switched from shnex:nodes to shnex:focusNode #525

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Aug 26, 2025
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#514: Renamed shnex:path to shnex:pathValues and switched from shnex:nodes to shnex:focusNode #525

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#514: Renamed shnex:path to shnex:pathValues and shnex:nodes to shnex…
HolgerKnublauch Aug 24, 2025
9c1aab7
Merge branch 'gh-pages' into issue-514
HolgerKnublauch Aug 25, 2025
59d8c1a
Finished renaming, clean up
HolgerKnublauch Aug 25, 2025
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156 changes: 93 additions & 63 deletions shacl12-node-expr/index.html
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Expand Up @@ -600,8 +600,8 @@ <h2>Getting started with Node Expressions</h2>
<p>
The following diagram illustrates how this node expression is interpreted, from a logical point of view.
During validation, a SHACL processor will determine the <a>target</a> nodes of the shape
by evaluating the <a>filterShape expression</a>.
However, the filterShape expression first evaluates its input expression, which is specified via <code>sh:nodes</code>
by evaluating the <a>filter shape expression</a>.
However, the filter shape expression first evaluates its input expression, which is specified via <code>sh:nodes</code>
and is an <a>instancesOf expression</a>.
This will produce all instances of the given class, <code>ex:Company</code>.
The <code>shnex:filterShape</code> is then applied to all of these instances, to keep only the companies
Expand Down Expand Up @@ -669,7 +669,7 @@ <h2>Getting started with Node Expressions</h2>
sh:datatype xsd:integer ;
sh:values <b>[
shnex:count [
shnex:path ex:employee ;
shnex:pathValues ex:employee ;
]
]</b> .
</div>
Expand Down Expand Up @@ -859,14 +859,14 @@ <h3>List Parameter Functions</h3>
sh:values <b>[
ex:coalesce (
[
# This is a path expression that is expected to return zero or one values
shnex:path ex:fullName ;
# This is a path values expression that is expected to return zero or one values
shnex:pathValues ex:fullName ;
]
[
ex:concat (
[ shnex:path ex:firstName ] # Path expression with at most one value
[ shnex:pathValues ex:firstName ] # Path values expression with at most one value
" " # A constant literal expression
[ shnex:path ex:lastName ] # Path expression with at most one value
[ shnex:pathValues ex:lastName ] # Path values expression with at most one value
)
]
)
Expand Down Expand Up @@ -1055,7 +1055,7 @@ <h3>List Expressions</h3>
sh:values [
shnex:nodes [
# This returns all transitive superclasses of the current focus node
shnex:path [ sh:zeroOrMorePath rdfs:subClassOf ] ;
shnex:pathValues [ sh:zeroOrMorePath rdfs:subClassOf ] ;
] ;
# This removes any superclasses that are in the list below
shnex:minus <b>( owl:Thing rdfs:Resource )</b> ;
Expand All @@ -1069,12 +1069,12 @@ <h3>List Expressions</h3>
</p>
</section>

<section id="PathExpression">
<h3>Path Expressions</h3>
<section id="PathValuesExpression">
<h3>Path Values Expressions</h3>
<p class="syntax">
<span data-syntax-rule="PathExpression-syntax">
<span data-syntax-rule="PathValuesExpression-syntax">
A <a>blank node</a> that is the <a>subject</a> of the following properties
is called a <dfn>path expression</dfn> with the <a>function name</a> <code>shnex:PathExpression</code>:
is called a <dfn>path values expression</dfn> with the <a>function name</a> <code>shnex:PathValuesExpression</code>:
<table class="term-table">
<thead>
<th>Property</th>
Expand All @@ -1083,7 +1083,7 @@ <h3>Path Expressions</h3>
</thead>
<tbody>
<tr>
<td><b><code>shnex:path</code></b></td>
<td><b><code>shnex:pathValues</code></b></td>
<td>
Must be a <a>well-formed</a> <a>SHACL property path</a>.
</td>
Expand All @@ -1092,41 +1092,49 @@ <h3>Path Expressions</h3>
</td>
</tr>
<tr>
<td><code>shnex:nodes</code></td>
<td><code>shnex:focusNode</code></td>
<td>
Optional, must be a <a>well-formed</a> <a>node expression</a>.
</td>
<td>
A node expression producing the <a>focus nodes</a>, defaulting
to the current focus node from the evaluation context.
A node expression producing the <a>focus node</a>,
defaulting to the current focus node from the evaluation context.
</td>
</tr>
</tbody>
</table>
</span>
</p>
<div class="def" id="PathExpression-evaluation">
<div class="def-header">EVALUATION OF PATH EXPRESSIONS</div>
<div class="def" id="PathValuesExpression-evaluation">
<div class="def-header">EVALUATION OF PATH VALUES EXPRESSIONS</div>
<p>
Let <code>path</code> be the <a>value</a> of <code>shnex:path</code>,
and <code>nodes</code> be the <a>value</a> of <code>shnex:nodes</code> in the <a>path expression</a>.
If <code>shnex:nodes</code> is not given, <code>nodes</code> is the list consistent of exactly the <a>focus node</a>.
Let <code>N</code> be the nodes produced by <code>evalExpr(nodes, focusGraph, focusNode, scope)</code>.
The <a>output nodes</a> of the <a>path expression</a> are the list of <a>nodes</a> produced by concatenating
the <a>value nodes</a> of the <code>path</code> at each <a>node</a> in <code>N</code>.
<span class="todo">TODO: Clarify if those can contain duplicates.</span>
Let <code>$pathValues</code> be the <a>value</a> of <code>shnex:pathValues</code>,
and <code>$focusNode</code> be the <a>value</a> of <code>shnex:focusNode</code> in a <a>path values expression</a>.
If <code>shnex:focusNode</code> is not given, <code>$focusNode</code> is the list consisting of exactly the <a>focus node</a>
from the evaluation context.<br /><br />
Let <code>N</code> be the nodes produced by <code>evalExpr($focusNode, focusGraph, focusNode, scope)</code>.
If <code>N</code> has 0 members, then the <a>output nodes</a> are the empty list.
If <code>N</code> has more than 1 member, an <a>evaluation failure</a> is reported.
Otherwise, the <a>output nodes</a> of the <a>path values expression</a> are the list of <a>value nodes</a> of the <code>path</code>
for the (only) member of <code>N</code>.
</p>
</div>
<p><em>The remainder of this section is informative.</em></p>
<p>
The following example illustrates the use of a <a>path expression</a> to compute the value
Note that by definition, the <a>value nodes</a> of a property shape may be derived properties,
based on <code>sh:values</code> or <code>sh:defaultValue</code> expressions.
This means that if the provided <code>shnex:pathValues</code> path is an <a>IRI</a>, then a path values expression
may cause the evaluation of other node expressions, as a simple kind of rule chaining.
</p>
<p>
The following example illustrates the use of a <a>path values expression</a> to compute the value
of the property <code>ex:topConceptCount</code>.
The path expression returns the values of <code>skos:hasTopConcept</code> at each <code>skos:ConceptScheme</code>
and these are processed by the <a href="#CountExpression"><code>shnex:count</code></a> to return the
The expression returns the values of <code>skos:hasTopConcept</code> for the current <code>skos:ConceptScheme</code>
and these values are processed by the <a href="#CountExpression"><code>shnex:count</code></a> to return the
number of top concepts.
</p>
<p>
<aside class="example" title="TODO">
<aside class="example" title="A path values expression computing the number of top concepts in a scheme">
<div class="shapes-graph">
<div class="turtle">
skos:ConceptScheme
Expand All @@ -1141,18 +1149,40 @@ <h3>Path Expressions</h3>
sh:maxCount 1 ;
sh:name "top concept count" ;
sh:values [
shnex:count [
<b>shnex:path skos:hasTopConcept</b> ;
] ;
shnex:count <b>[
shnex:pathValues skos:hasTopConcept ;
]</b> ;
] .
</div>
<div class="jsonld">
TODO
</div>
</div>
</aside>
<p>
The next example illustrates the use of a <a>path values expression</a> together with a specific focus node
(instead of the default focus node provided by the evaluation context).
The shape targets all <a>subjects</a> that have <code>skos:Concept</code> as their <code>rdf:type</code>
with a dynamically computed <code>sh:targetNode</code> expression.
In other words, the target nodes are the direct instances of <code>skos:Concept</code> based on asserted
<code>rdf:type</code> triples, not including the subclasses of <code>skos:Concept</code>.
</p>
<aside class="example" title="A shape that targets the direct instances of skos:Concept, using a path values expression">
<div class="shapes-graph">
<div class="turtle">
ex:DirectInstancesOfConceptShape
a sh:NodeShape ;
sh:targetNode <b>[
shnex:pathValues [ sh:inversePath rdf:type ] ;
shnex:focusNode skos:Concept ;
]</b> .
</div>
<div class="jsonld">
TODO
</div>
</div>
</aside>
</p>
<p class="todo">TODO: Add second example that uses shnex:nodes</p>
</section>

<section id="ExistsExpression">
Expand Down Expand Up @@ -1279,15 +1309,15 @@ <h3>If Expressions</h3>
sh:path ex:fillColor ;
sh:datatype xsd:string ;
sh:name "fill color" ;
sh:values [
<b>shnex:if [
sh:values <b>[
shnex:if [
shnex:exists [
shnex:path ex:capitalOf ;
shnex:pathValues ex:capitalOf ;
] ;
] ;
shnex:then "blue" ;
shnex:else "red" ;</b>
] .
shnex:else "red" ;
]</b> .
</div>
<div class="jsonld">
TODO
Expand Down Expand Up @@ -1360,16 +1390,16 @@ <h3>Distinct Expressions</h3>
a sh:PropertyShape ;
sh:path ex:superClassesIncludingRoot ;
sh:description "The superclasses of this, always including rdfs:Resource." ;
sh:values [
<b>shnex:distinct [
sh:values <b>[
shnex:distinct [
shnex:union (
[
shnex:path [ sh:zeroOrMorePath rdfs:subClassOf ] ;
shnex:pathValues [ sh:zeroOrMorePath rdfs:subClassOf ] ;
]
( rdfs:Resource )
)
] ;</b>
] .</b>
]</b> ;
] .
</div>
<div class="jsonld">
TODO
Expand Down Expand Up @@ -1426,12 +1456,12 @@ <h3>Intersection Expressions</h3>
<div class="turtle">
ex:DualCitizenShape
a sh:NodeShape ;
sh:targetNode [
<b>shnex:intersection (
sh:targetNode <b>[
shnex:intersection (
[ shnex:instancesOf ex:Australian ]
[ shnex:instancesOf ex:German ]
)</b>
] .
)
]</b> .
</div>
<div class="jsonld">
TODO
Expand Down Expand Up @@ -1540,11 +1570,11 @@ <h3>Minus Expressions</h3>
</section>

<section id="FilterShapeExpression">
<h3>FilterShape Expressions</h3>
<h3>Filter Shape Expressions</h3>
<p class="syntax">
<span data-syntax-rule="FilterShapeExpression-syntax">
A <a>blank node</a> that is the <a>subject</a> of the following properties
is called a <dfn>filterShape expression</dfn> with the <a>function name</a> <code>shnex:FilterShapeExpression</code>:
is called a <dfn>filter shape expression</dfn> with the <a>function name</a> <code>shnex:FilterShapeExpression</code>:
<table class="term-table">
<thead>
<th>Property</th>
Expand Down Expand Up @@ -1575,11 +1605,11 @@ <h3>FilterShape Expressions</h3>
</span>
</p>
<div class="def" id="FilterShapeExpression-evaluation">
<div class="def-header">EVALUATION OF FILTERSHAPE EXPRESSIONS</div>
<div class="def-header">EVALUATION OF FILTER SHAPE EXPRESSIONS</div>
<p>
Let <code>filterShape</code> be the <a>value</a> of <code>shnex:filterShape</code>,
and <code>nodes</code> be the <a>value</a> of <code>shnex:nodes</code> in a <a>filterShape expression</a>.
The <a>output nodes</a> of the <a>filterShape expression</a> are the <a>output nodes</a> of
and <code>nodes</code> be the <a>value</a> of <code>shnex:nodes</code> in a <a>filter shape expression</a>.
The <a>output nodes</a> of the <a>filter shape expression</a> are the <a>output nodes</a> of
<code>evalExpr(nodes, focusGraph, focusNode, scope)</code> except those that do not <a>conform</a> to
the <a>shape</a> <code>filterShape</code>, preserving the order in the list.
</p>
Expand All @@ -1604,7 +1634,7 @@ <h3>FilterShape Expressions</h3>
sh:class ex:Person ;
sh:values <b>[
shnex:nodes</b> [
shnex:path ex:child ;
shnex:pathValues ex:child ;
] ;
<b>shnex:filterShape [
sh:property [
Expand Down Expand Up @@ -1694,7 +1724,7 @@ <h3>Limit Expressions</h3>
sh:values <b>[
shnex:nodes</b> [
shnex:nodes [
shnex:path ex:child ;
shnex:pathValues ex:child ;
] ;
shnex:orderBy ex:dateOfBirth ;
] ;
Expand Down Expand Up @@ -1781,7 +1811,7 @@ <h3>Offset Expressions</h3>
sh:values <b>[
shnex:nodes</b> [
shnex:nodes [
shnex:path ex:child ;
shnex:pathValues ex:child ;
] ;
shnex:orderBy ex:dateOfBirth ;
] ;
Expand Down Expand Up @@ -1867,7 +1897,7 @@ <h3>Count Expressions</h3>
sh:name "top concept count" ;
sh:values [
shnex:count [
shnex:path skos:hasTopConcept ;
shnex:pathValues skos:hasTopConcept ;
] ;
] .
</div>
Expand Down Expand Up @@ -1940,7 +1970,7 @@ <h3>Min Expressions</h3>
sh:name "min start date" ;
sh:values [
shnex:min [
shnex:path ( ex:employee ex:startDate ) ;
shnex:pathValues ( ex:employee ex:startDate ) ;
] ;
] .
</div>
Expand Down Expand Up @@ -2035,8 +2065,8 @@ <h3>Sum Expressions</h3>
<p>
Note that <code>shnex:sum</code> needs to be used with care and may be often misunderstood,
when used with property paths.
The problem is that when a <a>path expression</a> is used as input to a <a>sum expression</a>,
the path expression will have eliminated duplicates before they can be processed by the <code>shnex:sum</code>.
The problem is that when a <a>path values expression</a> is used as input to a <a>sum expression</a>,
the path values expression will have eliminated duplicates before they can be processed by the <code>shnex:sum</code>.
As a result, only the distinct values will be added up.
</p>
<p class="todo">TODO: Find good example, or drop the feature if none makes sense</p>
Expand Down Expand Up @@ -2183,7 +2213,7 @@ <h3>sh:expression</h3>
[
sparql:ucase (
[
shnex:path ( ex:country ex:code )
shnex:pathValues ( ex:country ex:code )
shnex:nodes [ shnex:var "focusNode" ]
]
)
Expand Down Expand Up @@ -2292,7 +2322,7 @@ <h3>sh:nodeByExpression</h3>
The following example demonstrates how <code>sh:nodeByExpression</code> could be used in the context of the <a href="https://www.w3.org/TR/vocab-data-cube/">W3C Data Cube Vocabulary</a>.
Building upon examples 5 and 6 from the Data Cube Vocabulary documentation, Data Structure Definition is extended with the property <code>eg:hasShape</code>,
which links to an associated <a>node shape</a> to which relevant <code>qb:Observation</code> instances must conform.
To validate that every <code>qb:Observation</code> instance conforms to the appropriate shape, <code>sh:nodeByExpression</code> with a <a>Path Expression</a>
To validate that every <code>qb:Observation</code> instance conforms to the appropriate shape, <code>sh:nodeByExpression</code> with a <a>path values expression</a>
is used to locate the shape at the property path <code>qb:dataSet/qb:structure/eg:hasShape</code> from each <code>qb:Observation</code> instance.
</p>
<aside class="example">
Expand Down Expand Up @@ -2325,7 +2355,7 @@ <h3>sh:nodeByExpression</h3>
a sh:NodeShape ;
sh:targetClass qb:Observation ;
sh:nodeByExpression [
shnex:path (qb:dataSet qb:structure eg:hasShape) ;
shnex:pathValues (qb:dataSet qb:structure eg:hasShape) ;
] .
</div>
<div class="jsonld">
Expand Down Expand Up @@ -2403,7 +2433,7 @@ <h3>sh:nodeByExpression</h3>
"@id": "qb:Observation"
},
"sh:nodeByExpression": {
"shnex:path": {
"shnex:pathValues": {
"@list": [
{
"@id": "qb:dataSet"
Expand Down
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