From 6c2423916b26e2d2e966ee79340aec07b29008d1 Mon Sep 17 00:00:00 2001
From: overlookmotel <theoverlookmotel@gmail.com>
Date: Tue, 21 Nov 2023 00:41:19 +0000
Subject: [PATCH] Replace dictionary object with Map in Separate namespace for
 private vars in unmangled var name transform [perf]

---
 lib/serialize/varNames.js | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/serialize/varNames.js b/lib/serialize/varNames.js
index dd08580f..18e5d8c9 100644
--- a/lib/serialize/varNames.js
+++ b/lib/serialize/varNames.js
@@ -92,7 +92,7 @@ const NAME_REGEX = /^(.*?)(?:\$(\d+))?$/;
 class UnmangledVarNameFactory extends VarNameFactory {
 	constructor(reservedNames) {
 		super(reservedNames);
-		this.used = Object.create(null);
+		this.used = new Map();
 	}
 
 	transform(name, isPrivate) {
@@ -100,8 +100,7 @@ class UnmangledVarNameFactory extends VarNameFactory {
 		const [, nameWithoutPostfix, numStr] = name.match(NAME_REGEX);
 		let num = numStr ? numStr * 1 : -1;
 
-		const {used} = this;
-		const usedNum = used[nameWithoutPostfix];
+		const usedNum = this.used.get(nameWithoutPostfix);
 		if (usedNum !== undefined && num <= usedNum) num = usedNum + 1;
 
 		let outName = nameWithoutPostfix;
@@ -111,7 +110,7 @@ class UnmangledVarNameFactory extends VarNameFactory {
 			num++;
 		}
 
-		used[nameWithoutPostfix] = num;
+		this.used.set(nameWithoutPostfix, num);
 
 		return outName;
 	}