From dd8ec4e291188c48448021d651508d3fe3ee3466 Mon Sep 17 00:00:00 2001
From: Richard Hansen <rhansen@rhansen.org>
Date: Wed, 20 Oct 2021 19:15:30 -0400
Subject: [PATCH] Changeset: Remove unused `lastIndex()` method from op
 iterator

---
 CHANGELOG.md               | 3 ++-
 src/static/js/Changeset.js | 9 ---------
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index da1fb2068..450a2d8c1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -39,7 +39,8 @@
     * `readonly`: Deprecated; use the new `readOnly` property instead.
     * `rev`: Deprecated.
   * Changes to the `src/static/js/Changeset.js` library:
-    * `opIterator()`: The unused start index parameter has been removed.
+    * `opIterator()`: The unused start index parameter has been removed, as has
+      the unused `lastIndex()` method on the returned object.
 
 ### Notable enhancements
 
diff --git a/src/static/js/Changeset.js b/src/static/js/Changeset.js
index 796ae9130..0d3d9991c 100644
--- a/src/static/js/Changeset.js
+++ b/src/static/js/Changeset.js
@@ -134,7 +134,6 @@ exports.newLen = (cs) => exports.unpack(cs).newLen;
  *
  * @typedef {object} OpIter
  * @property {Function} hasNext -
- * @property {Function} lastIndex -
  * @property {Function} next -
  */
 
@@ -146,14 +145,9 @@ exports.newLen = (cs) => exports.unpack(cs).newLen;
  */
 exports.opIterator = (opsStr) => {
   const regex = /((?:\*[0-9a-z]+)*)(?:\|([0-9a-z]+))?([-+=])([0-9a-z]+)|\?|/g;
-  let curIndex = 0;
-  let prevIndex = curIndex;
 
   const nextRegexMatch = () => {
-    prevIndex = curIndex;
-    regex.lastIndex = curIndex;
     const result = regex.exec(opsStr);
-    curIndex = regex.lastIndex;
     if (result[0] === '?') {
       exports.error('Hit error opcode in op stream');
     }
@@ -178,12 +172,9 @@ exports.opIterator = (opsStr) => {
 
   const hasNext = () => !!(regexResult[0]);
 
-  const lastIndex = () => prevIndex;
-
   return {
     next,
     hasNext,
-    lastIndex,
   };
 };