es-next-tools/dist/structures/Queue.js

A comprehensive utility library for JavaScript and TypeScript that provides a wide range of functions for common programming tasks, including mathematical operations, date manipulations, array and object handling, string utilities, and more.

/**
 * Represents a queue data structure.
 * @template T The type of elements in the queue.
 * @example
 * const queue = new Queue<number>();
 * queue.enqueue(1).enqueue(2);
 * console.log(queue.dequeue()); // 1
 */
export class Queue {
    items = [];
    /**
     * Adds an item to the end of the queue.
     * @param {T} item - The item to add to the queue.
     * @returns {Queue<T>} The queue instance for chaining.
     */
    enqueue(item) {
        this.items.push(item);
        return this;
    }
    /**
     * Removes and returns the item at the front of the queue.
     * @returns {T} The item at the front of the queue.
     * @throws {Error} If the queue is empty.
     */
    dequeue() {
        if (this.isEmpty()) {
            throw new Error('Queue is empty.');
        }
        return this.items.shift();
    }
    /**
     * Returns the number of items in the queue.
     * @returns {number} The size of the queue.
     */
    size() {
        return this.items.length;
    }
    /**
     * Returns the item at the front of the queue without removing it.
     * @returns {T | undefined} The item at the front of the queue, or undefined if the queue is empty.
     */
    peek() {
        return this.items[0];
    }
    /**
     * Checks if the queue is empty.
     * @returns {boolean} True if the queue is empty, false otherwise.
     */
    isEmpty() {
        return this.items.length === 0;
    }
    /**
     * Checks if the queue contains a specific item.
     * @param {T} item - The item to check for.
     * @returns {boolean} True if the item is in the queue, false otherwise.
     */
    contains(item) {
        return this.items.includes(item);
    }
    /**
     * Creates a copy of the queue.
     * @returns {Queue<T>} A new queue instance with the same items.
     */
    copy() {
        const newQueue = new Queue();
        newQueue.items = [...this.items];
        return newQueue;
    }
    /**
     * Serializes the queue to a JSON string.
     * @returns {string} The serialized queue.
     */
    serialize() {
        return JSON.stringify(this.items);
    }
    /**
     * Deserializes a JSON string to populate the queue.
     * @param {string} data - The JSON string to deserialize.
     */
    deserialize(data) {
        this.items = JSON.parse(data);
    }
}