From 0fbd32e7c3811e3a1c2bd16130cbe5358c4d3d7c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martynas=20Jusevi=C4=8Dius?= <martynas@atomgraph.com>
Date: Mon, 13 Jul 2026 22:54:02 +0300
Subject: [PATCH] Hoist the loop-invariant ontology-URI lookup out of the label
 predicate

SaxonJS does not hoist local:ontology-uri($vocab) out of the predicate
in local:ontology-label, so the whole vocabulary document was rescanned
once per description element - quadratic on the striped, 1400-description
dcterms.rdf and ~1.4s of every editor boot spent in init-overlay.

Binding the URI to a variable first makes the scan linear: init-overlay
drops from ~1430ms to ~20ms, and the toolbar appears at ~0.7s instead of
~2.1s after navigation (measured headless on localhost).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 src/vocab.xsl | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/vocab.xsl b/src/vocab.xsl
index 93e724f..a9d1d1b 100644
--- a/src/vocab.xsl
+++ b/src/vocab.xsl
@@ -53,8 +53,11 @@ version="3.0">
         <xsl:param name="vocab" as="document-node()"/>
         <xsl:param name="href" as="xs:string"/>
 
+        <!-- bound outside the predicate: SaxonJS does not hoist the loop-invariant
+             call, and re-evaluating it per scanned element is quadratic -->
+        <xsl:variable name="ontology-uri" as="xs:string?" select="local:ontology-uri($vocab)"/>
         <xsl:variable name="ontology" as="element()*"
-            select="$vocab/rdf:RDF/*[@rdf:about = local:ontology-uri($vocab)]"/>
+            select="$vocab/rdf:RDF/*[@rdf:about = $ontology-uri]"/>
         <xsl:sequence select="($ontology/@dc11:title, $ontology/dc11:title, $ontology/@dct:title, $ontology/dct:title,
             $ontology/@rdfs:label, $ontology/rdfs:label, $href)[1] ! string(.)"/>
     </xsl:function>