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Add missing comparison operators for triple terms #289

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5603a21
Add missing value comparison operators for triple terms
rubensworks Sep 25, 2025
e9924bd
Support triple terms in ORDER BY
rubensworks Sep 25, 2025
7213f87
Fix links to compareTripleTerm
rubensworks Sep 26, 2025
cba3ec1
Apply suggestions from code review
rubensworks Sep 26, 2025
3f20202
Link to SUBJECT, PREDICATE, and OBJECT functions
rubensworks Sep 26, 2025
189d62e
Remove obsolete sentence about triple terms in operator mapping table
rubensworks Sep 26, 2025
def10d9
Use term1/2 instead of A/B in func-compareTripleTerm
rubensworks Sep 26, 2025
bf53dac
Clarify next step in func-compareTripleTerm
rubensworks Sep 26, 2025
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107 changes: 100 additions & 7 deletions spec/index.html
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Original file line number Diff line number Diff line change
Expand Up @@ -3674,7 +3674,7 @@ <h3>ORDER BY</h3>
<p>The <a href="#op_lt">"&lt;" operator</a> (see the <a href="#OperatorMapping">Operator
Mapping</a> and <a href="#operatorExtensibility">17.3.1 Operator Extensibility</a>) defines
the relative order of pairs of <code>numerics</code>,
<code>xsd:strings</code>, <code>xsd:booleans</code> and <code>xsd:dateTimes</code>. Pairs of
<code>xsd:strings</code>, <code>xsd:booleans</code>, <code>xsd:dateTimes</code>, and <a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Terms</a>. Pairs of
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Making source more readable. A little manual tidy.

Suggested change
<code>xsd:strings</code>, <code>xsd:booleans</code>, <code>xsd:dateTimes</code>, and <a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Terms</a>. Pairs of
<code>xsd:strings</code>, <code>xsd:booleans</code>, <code>xsd:dateTimes</code>, and
<a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Terms</a>. Pairs of

IRIs are ordered by comparing them as literals with datatype <code>xsd:string</code>.</p>
<p>SPARQL also fixes an order between some kinds of RDF terms that would not otherwise be
ordered:</p>
Expand All @@ -3683,6 +3683,7 @@ <h3>ORDER BY</h3>
<li>Blank nodes</li>
<li>IRIs</li>
<li>RDF literals</li>
<li>Triple terms</li>
</ol>
<p>SPARQL does not define a total ordering of all possible RDF terms. Here are a few examples
of pairs of terms for which the relative order is undefined:</p>
Expand Down Expand Up @@ -5418,9 +5419,7 @@ <h3>Operator Mapping</h3>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td>
( A.subject = B.subject ) <a href="#logical-and-operator" class="SPARQLoperator">&amp;&amp;</a><br/>
( A.predicate = B.predicate ) <a href="#logical-and-operator" class="SPARQLoperator">&amp;&amp;</a><br/>
( A.object = B.object )
<a data-cite="XPATH-FUNCTIONS-31#func-numeric-equal">op:numeric-equal</a>(<a href="#func-sameTerm">compareTripleTerm</a>(A, B), 0)
</td>
<td>xsd:boolean</td>
</tr>
Expand All @@ -5445,9 +5444,7 @@ <h3>Operator Mapping</h3>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td>
( A.subject != B.subject ) <a href="#logical-or-operator" class="SPARQLoperator">||</a><br/>
( A.predicate != B.predicate ) <a href="#logical-or-operator" class="SPARQLoperator">||</a><br/>
( A.object != B.object )
<a data-cite="XPATH-FUNCTIONS-31#func-not">fn:not</a>(<a data-cite="XPATH-FUNCTIONS-31#func-numeric-equal">op:numeric-equal</a>(<a href="#func-sameTerm">compareTripleTerm</a>(A, B), 0))
</td>
<td>xsd:boolean</td>
</tr>
Expand All @@ -5469,6 +5466,42 @@ <h3>Operator Mapping</h3>
</td>
<td>xsd:boolean</td>
</tr>
<tr>
<th><a href="#rRelationalExpression" title="RelationalExpression">A <span class="FAOTtoken">&lt;</span> B</a></th>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td>
<a data-cite="XPATH-FUNCTIONS-31#func-numeric-equal">op:numeric-equal</a>(<a href="#func-sameTerm">compareTripleTerm</a>(A, B), -1)
</td>
<td>xsd:boolean</td>
</tr>
<tr>
<th><a href="#rRelationalExpression" title="RelationalExpression">A <span class="FAOTtoken">&lt;=</span> B</a></th>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td>
<a data-cite="XPATH-FUNCTIONS-31#func-not">fn:not</a>(<a data-cite="XPATH-FUNCTIONS-31#func-numeric-equal">op:numeric-equal</a>(<a href="#func-sameTerm">compareTripleTerm</a>(A, B), 1))
</td>
<td>xsd:boolean</td>
</tr>
<tr>
<th><a href="#rRelationalExpression" title="RelationalExpression">A <span class="FAOTtoken">&gt;</span> B</a></th>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td>
<a data-cite="XPATH-FUNCTIONS-31#func-numeric-equal">op:numeric-equal</a>(<a href="#func-sameTerm">compareTripleTerm</a>(A, B), 1)
</td>
<td>xsd:boolean</td>
</tr>
<tr>
<th><a href="#rRelationalExpression" title="RelationalExpression">A <span class="FAOTtoken">&gt;=</span> B</a></th>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td><span class="type RDFterm"><a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Term</a></span></td>
<td>
<a data-cite="XPATH-FUNCTIONS-31#func-not">fn:not</a>(<a data-cite="XPATH-FUNCTIONS-31#func-numeric-equal">op:numeric-equal</a>(<a href="#func-sameTerm">compareTripleTerm</a>(A, B), -1))
</td>
<td>xsd:boolean</td>
</tr>
</tbody>
</table>
<p>
Expand Down Expand Up @@ -6084,6 +6117,66 @@ <h5>sameValue</h5>
</p>
</section>

<section id="func-compareTripleTerm">
<h5>compareTripleTerm</h5>
<pre class="prototype nohighlight">
<span class="return">xsd:integer</span> <span class="operator" style="text-transform: none;">compareTripleTerm</span> (<span class="type"><span class="type RDFterm">Triple term</span></span> <span class="name">term1</span>, <span class="type"><span class="type RDFterm">Triple term</span></span> <span class="name">term2</span>)
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Making source more readable. A little manual tidy.

Suggested change
<span class="return">xsd:integer</span> <span class="operator" style="text-transform: none;">compareTripleTerm</span> (<span class="type"><span class="type RDFterm">Triple term</span></span> <span class="name">term1</span>, <span class="type"><span class="type RDFterm">Triple term</span></span> <span class="name">term2</span>)
<span class="return">xsd:integer</span>
<span class="operator" style="text-transform: none;">compareTripleTerm</span>
(<span class="type"><span class="type RDFterm">Triple term</span></span>
<span class="name">term1</span>,
<span class="type"><span class="type RDFterm">Triple term</span></span>
<span class="name">term2</span>)

</pre>

<p>This function cannot be used directly in expressions. The purpose
of this function is to define the semantics of value-comparison operators on <a data-cite="RDF12-CONCEPTS#dfn-triple-term">Triple Terms</a> such as "=" and "&lt;" operator
in Section <a href="#OperatorMapping" class="sectionRef"></a>.
</p>

<p>This function returns -1, 0, 1, or throws an error.
Comparison is performed pairwise on the components of the triple terms in the order subject, predicate, object until the result is determined.
Comment on lines +6128 to +6129
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Making source more readable. A little manual tidy.

Suggested change
<p>This function returns -1, 0, 1, or throws an error.
Comparison is performed pairwise on the components of the triple terms in the order subject, predicate, object until the result is determined.
<p>This function returns `-1`, `0`, or `1`, or throws an error.
Comparison is performed pairwise on the components of the triple terms
in the order subject, predicate, object until the result is determined.

An error is thrown if comparing two components results in an error.</p>

<p>The result of this function is determined by going through the following steps.</p>

<ol>
<li>If <code>SUBJECT(A) = SUBJECT(B)</code> evaluates to true, go to the next step.
If <code>SUBJECT(A) &lt; SUBJECT(B)</code> evaluates to true, return -1.
If <code>SUBJECT(A) &gt; SUBJECT(B)</code> evaluates to true, return 1.
If any of the evalutions cause an error, raise an error.
</li>
<li>If <code>PREDICATE(A) = PREDICATE(B)</code> evaluates to true, go to the next step.
If <code>PREDICATE(A) &lt; PREDICATE(B)</code> evaluates to true, return -1.
If <code>PREDICATE(A) &gt; PREDICATE(B)</code> evaluates to true, return 1.
If any of the evalutions cause an error, raise an error.
</li>
<li>If <code>OBJECT(A) = OBJECT(B)</code> evaluates to true, return 0.
If <code>OBJECT(A) &lt; OBJECT(B)</code> evaluates to true, return -1.
If <code>OBJECT(A) &gt; OBJECT(B)</code> evaluates to true, return 1.
If any of the evalutions cause an error, raise an error.
</li>
</ol>

<p>Examples:</p>
<div class="result">
<table>
<tbody>
<tr>
<th>compareTripleTerm</th>
<th>Results</th>
</tr>
<tr>
<td><code>compareTripleTerm(&lt;&lt;(:s :p :o)&gt;&gt;, &lt;&lt;(:s :p :o)&gt;&gt;)</code></td>
<td>0</td>
</tr>
<tr>
<td><code>compareTripleTerm(&lt;&lt;(:s :p 123)&gt;&gt;, &lt;&lt;(:s :p 124)&gt;&gt;)</code></td>
<td>-1</td>
</tr>
<tr>
<td><code>compareTripleTerm(&lt;&lt;(:s :p 123)&gt;&gt;, &lt;&lt;(:s :p 122)&gt;&gt;)</code></td>
<td>1</td>
</tr>
</tbody>
</table>
</div>
</section>

<section id="func-isIRI">
<span id="func-isURI"></span>
<h5>isIRI</h5>
Expand Down
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