@datastructures-js/deque

A performant double-ended queue (deque) implementation in javascript.

Contents

• Install
• require
• import
• API
  • constructor
  • Deque.fromArray
  • pushFront
  • pushBack
  • front
  • back
  • popFront
  • popBack
  • isEmpty
  • size
  • clone
  • toArray
  • clear
• Build
• License

Install

npm install --save @datastructures-js/deque

require

const { Deque } = require('@datastructures-js/deque');

import

import { Deque } from '@datastructures-js/deque';

API

constructor

JS

// empty queue
const deque = new Deque();

// from an array
const deque = new Deque([1, 2, 3]);

TS

// empty queue
const deque = new Deque<number>();

// from an array
const deque = new Deque<number>([1, 2, 3]);

Deque.fromArray

JS

// empty queue
const deque = Deque.fromArray([]);

// with elements
const list = [10, 3, 8, 40, 1];
const deque = Deque.fromArray(list);

// If the list should not be mutated, use a copy of it.
const deque = Deque.fromArray(list.slice());

TS

// empty queue
const deque = Deque.fromArray<number>([]);

// with elements
const list = [10, 3, 8, 40, 1];
const deque = Deque.fromArray<number>(list);

pushFront

adds an element at the front of the queue.

deque.pushFront(30).pushFront(20).pushFront(10);

pushBack

adds an element at the back of the queue.

deque.pushBack(40).pushBack(50).pushBack(60);

front

peeks on the front element of the queue.

console.log(deque.front()); // 10

back

peeks on the back element of the queue.

console.log(deque.back()); // 60

popFront

removes and returns the front element in the queue.

console.log(deque.popFront()); // 10
console.log(deque.front()); // 20

popBack

removes and returns the back element in the queue.

console.log(deque.popBack()); // 60
console.log(deque.back()); // 50

isEmpty

checks if the queue is empty.

console.log(deque.isEmpty()); // false

size

returns the number of elements in the queue.

console.log(deque.size()); // 4

clone

creates a shallow copy of the queue.

const deque2 = Deque.fromArray([{ id: 2 }, { id: 4 } , { id: 8 }]);
const clone =  deque2.clone();

clone.popFront();

console.log(deque2.front()); // { id: 2 }
console.log(clone.front()); // { id: 4 }

toArray

returns a copy of the remaining elements as an array.

console.log(deque.toArray()); // [ 20, 30, 40, 50 ]

clear

clears all elements from the queue.

deque.clear();
deque.size(); // 0

Build

grunt build

License

The MIT License. Full License is here