From 78768e00d4e966c6211bd88ec046f3bb369aa68b Mon Sep 17 00:00:00 2001
From: s2224834 <46319860+s2224834@users.noreply.github.com>
Date: Thu, 10 Jan 2019 18:44:50 +0000
Subject: [PATCH] Bombe: Firefox optimisation

Switch a couple of for of loops in the critical path for classic fors.
This loses about 10% performance in Chrome, but it brings Firefox
performance in line with Chrome's, rather than 2.5 times slower.
---
 src/core/lib/Bombe.mjs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/core/lib/Bombe.mjs b/src/core/lib/Bombe.mjs
index 8b781b68..7400c98a 100644
--- a/src/core/lib/Bombe.mjs
+++ b/src/core/lib/Bombe.mjs
@@ -514,7 +514,8 @@ export class BombeMachine {
         const idxPair = 26*j + i;
         this.wires[idxPair] = true;
 
-        for (const scrambler of this.scramblers[i]) {
+        for (let k=0; k<this.scramblers[i].length; k++) {
+            const scrambler = this.scramblers[i][k];
             const out = scrambler.transform(j);
             const other = scrambler.getOtherEnd(i);
             this.energise(other, out);
@@ -522,7 +523,8 @@ export class BombeMachine {
         if (i === j) {
             return;
         }
-        for (const scrambler of this.scramblers[j]) {
+        for (let k=0; k<this.scramblers[j].length; k++) {
+            const scrambler = this.scramblers[j][k];
             const out = scrambler.transform(i);
             const other = scrambler.getOtherEnd(j);
             this.energise(other, out);