https://github.com/blakeembrey/deque
JavaScript implementation of a double-ended queue
https://github.com/blakeembrey/deque
deque dequeue double-linked-list iterator linked-list queue stack
Last synced: about 2 months ago
JSON representation
JavaScript implementation of a double-ended queue
- Host: GitHub
- URL: https://github.com/blakeembrey/deque
- Owner: blakeembrey
- License: other
- Created: 2018-09-10T01:24:34.000Z (almost 7 years ago)
- Default Branch: master
- Last Pushed: 2023-12-07T08:05:26.000Z (over 1 year ago)
- Last Synced: 2025-04-15T06:13:12.472Z (about 2 months ago)
- Topics: deque, dequeue, double-linked-list, iterator, linked-list, queue, stack
- Language: TypeScript
- Size: 659 KB
- Stars: 18
- Watchers: 2
- Forks: 2
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Security: SECURITY.md
Awesome Lists containing this project
README
# Deque
[![NPM version][npm-image]][npm-url]
[![NPM downloads][downloads-image]][downloads-url]
[![Build status][travis-image]][travis-url]
[![Test coverage][coveralls-image]][coveralls-url]
> Deques are a generalization of stacks and queues (the name is pronounced "deck" and is short for "double-ended queue").
> -- [Python `collections`](https://docs.python.org/3/library/collections.html#collections.deque).
## Installation
```
npm install @blakeembrey/deque --save
```
## Usage
- `size` Returns the number of elements in the deque.
- `push(x)` Add `x` to right side of the deque.
- `pushLeft(x)` Add `x` to the left side of the deque.
- `clear()` Remove all elements from the deque leaving it with length 0.
- `extend(iterable)` Extend the right side of the deque by appending elements from iterable.
- `extendLeft(iterable)` Extend the left side of the deque by appending elements from iterable.
- `peek(i)` Return the element at index `i` in the deque.
- `indexOf(x, start?)` Return the position of `x` in the deque.
- `has(x)` Return a boolean indicating whether `x` is in the deque.
- `insert(i, x)` Insert `x` into the deque at position `i`.
- `pop()` Remove and return an element from the right side of the deque. If no elements are present, throws `RangeError`.
- `popLeft()` Return and return an element from the left side of the deque. If no elements are present, throws `RangeError`.
- `delete(i)` Delete the value at position `i`.
- `reverse()` Reverse the elements of the deque in-place.
- `rotate(n=1)` Rotate the deque `n` steps to the right.
- `entries()` Return an iterable of deque.
- `@@iterator()` Return an iterable of deque.
```js
import { Deque } from '@blakeembrey/deque'
const d = new Deque('ghi')
for (const value of d) {
console.log(value.toUpperCase()) //=> G H I
}
d.push('j')
d.pushLeft('f')
d //=> Deque(['f', 'g', 'h', 'i', 'j'])
d.pop() //=> 'j'
d.popLeft() //=> 'f'
Array.from(d) //=> ['g', 'h', 'i']
d.peek(0) //=> 'g'
d.peek(-1) //=> 'i'
d.extend('jkl')
d //=> Deque(['g', 'h', 'i', 'j', 'k', 'l'])
d.rotate(1)
d //=> Deque(['l', 'g', 'h', 'i', 'j', 'k'])
d.rotate(-1)
d //=> Deque(['g', 'h', 'i', 'j', 'k', 'l'])
const d2 = new Deque(d)
d2 //=> Deque(['g', 'h', 'i', 'j', 'k', 'l'])
```
## TypeScript
This project uses [TypeScript](https://github.com/Microsoft/TypeScript) and publishes definitions on NPM.
## Reference
Circular array implementation originally based on [`denque`](https://github.com/Salakar/denque) with additional optimizations.
## License
Apache 2.0
[npm-image]: https://img.shields.io/npm/v/@blakeembrey/deque.svg?style=flat
[npm-url]: https://npmjs.org/package/@blakeembrey/deque
[downloads-image]: https://img.shields.io/npm/dm/@blakeembrey/deque.svg?style=flat
[downloads-url]: https://npmjs.org/package/@blakeembrey/deque
[travis-image]: https://img.shields.io/travis/blakeembrey/deque.svg?style=flat
[travis-url]: https://travis-ci.org/blakeembrey/deque
[coveralls-image]: https://img.shields.io/coveralls/blakeembrey/deque.svg?style=flat
[coveralls-url]: https://coveralls.io/r/blakeembrey/deque?branch=master