From 6099ba186c38c854332ec483edd6cbca3cf94871 Mon Sep 17 00:00:00 2001
From: daurnimator <quae@daurnimator.com>
Date: Thu, 14 Dec 2017 14:55:32 +1100
Subject: src/lstrlib.js: Optimise array_cmp

Using .indexOf seems to benchmark faster than iterating
---
 src/lstrlib.js | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/lstrlib.js b/src/lstrlib.js
index 0572e95..362942d 100644
--- a/src/lstrlib.js
+++ b/src/lstrlib.js
@@ -965,12 +965,21 @@ const end_capture = function(ms, s, p) {
 
 /* Compare the elements of arrays 'a' and 'b' to see if they contain the same elements */
 const array_cmp = function(a, ai, b, bi, len) {
+    if (len === 0)
+        return true;
     let aj = ai+len;
-    for (; ai < aj; ai++, bi++) {
-        if (a[ai] !== b[bi])
+    loop: for (;;) {
+        ai = a.indexOf(b[bi], ai);
+        if (ai === -1 || ai >= aj)
             return false;
+        for (let j = 1; j < len; j++) {
+            if (a[ai+j] !== b[bi+j]) {
+                ai++;
+                continue loop;
+            }
+        }
+        return true;
     }
-    return true;
 };
 
 const match_capture = function(ms, s, l) {
-- 
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