From b1577cd97272354f930ee506a09a4d930903c68c Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=B4me=20Benoit?= <jerome.benoit@piment-noir.org>
Date: Mon, 15 Jan 2024 20:53:52 +0100
Subject: [PATCH] perf: use object literal in Deque doubly linked list
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Signed-off-by: Jérôme Benoit <jerome.benoit@piment-noir.org>
---
 src/deque.ts | 24 +++++++++---------------
 src/index.ts |  2 +-
 2 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/src/deque.ts b/src/deque.ts
index 44431789..027aa70d 100644
--- a/src/deque.ts
+++ b/src/deque.ts
@@ -1,19 +1,15 @@
 // Copyright Jerome Benoit. 2023. All Rights Reserved.
 
 /**
- * Linked list node.
+ * Linked list node interface.
  *
  * @typeParam T - Type of linked list node data.
  * @internal
  */
-export class LinkedListNode<T> {
-  public data: T
-  public next?: LinkedListNode<T>
-  public prev?: LinkedListNode<T>
-
-  public constructor (data: T) {
-    this.data = data
-  }
+export interface ILinkedListNode<T> {
+  data: T
+  next?: ILinkedListNode<T>
+  prev?: ILinkedListNode<T>
 }
 
 /**
@@ -24,8 +20,8 @@ export class LinkedListNode<T> {
  * @internal
  */
 export class Deque<T> {
-  private head?: LinkedListNode<T>
-  private tail?: LinkedListNode<T>
+  private head?: ILinkedListNode<T>
+  private tail?: ILinkedListNode<T>
   /** The size of the deque. */
   public size!: number
   /** The maximum size of the deque. */
@@ -42,11 +38,10 @@ export class Deque<T> {
    * @returns The new size of the queue.
    */
   public push (data: T): number {
-    const node = new LinkedListNode(data)
+    const node = { data, prev: this.tail }
     if (this.tail == null) {
       this.head = this.tail = node
     } else {
-      node.prev = this.tail
       this.tail = this.tail.next = node
     }
     return this.incrementSize()
@@ -59,11 +54,10 @@ export class Deque<T> {
    * @returns The new size of the queue.
    */
   public unshift (data: T): number {
-    const node = new LinkedListNode(data)
+    const node = { data, next: this.head }
     if (this.head == null) {
       this.head = this.tail = node
     } else {
-      node.next = this.head
       this.head = this.head.prev = node
     }
     return this.incrementSize()
diff --git a/src/index.ts b/src/index.ts
index 1548487f..eab1ab2b 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -74,5 +74,5 @@ export type {
   Writable
 } from './utility-types.js'
 export type { CircularArray } from './circular-array.js'
-export type { Deque, LinkedListNode } from './deque.js'
+export type { Deque, ILinkedListNode } from './deque.js'
 export { availableParallelism } from './utils.js'
-- 
2.34.1