From 49654160fa188ca5f6376602b41c9f33e80e764a Mon Sep 17 00:00:00 2001
From: Javier Sagredo <javier.sagredo@iohk.io>
Date: Thu, 7 May 2026 02:49:09 +0200
Subject: [PATCH] Dedupe the side-panel "Subclasses (in this program)" list

A single class can appear twice as a subclass of the same class
(e.g. `class (Foo a, Foo b) => Bar a b` produces two SuperclassEdges
with target Foo). The reverse-index push happens per-edge, which is
the right granularity for chain reasoning, but the side-panel list
was rendering each entry verbatim and so duplicated subclass names.
Add a per-render dedup set keyed on the subclass's qid so each
subclass shows up at most once.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 data/viewer.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/data/viewer.js b/data/viewer.js
index 362c98c..e8de238 100644
--- a/data/viewer.js
+++ b/data/viewer.js
@@ -1763,10 +1763,17 @@
         })
         .join('');
     const subEntries = subclassesByClass.get(cid) || [];
+    // Dedupe by subclass qid: a single class can list the same
+    // superclass twice in ciSuperclasses (e.g. `class (Foo a, Foo b)
+    // => Bar a b` produces two SuperclassEdges with the same target),
+    // which would otherwise show as duplicate rows here.
+    const seenSubs = new Set();
     const subs = subEntries.length === 0 ? '<dd><em>none</em></dd>' :
       subEntries
         .map(({subclass}) => {
           const sid = qid(subclass.ciName);
+          if (seenSubs.has(sid)) return '';
+          seenSubs.add(sid);
           return `<dd><a href="#" data-action="navigate-class" data-id="${escapeAttr(sid)}">` +
                  `${escape(subclass.ciName.qnName)}</a></dd>`;
         })
-- 
2.54.0