# @blakeembrey/deque

> Deques are a generalization of stacks and queues

Latest version **1.0.5** (published 2019-02-19) · Apache-2.0 license · 0 weekly downloads

## Install

```sh
npm install @blakeembrey/deque
pnpm add @blakeembrey/deque
yarn add @blakeembrey/deque
bun add @blakeembrey/deque
```

## Health

**Score 25/100 (F)** — status: abandoned.

Positive: has types; no vulnerabilities; high quality score.

Warnings: low downloads; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.0.5 |
| Published | 2019-02-19 |
| First published | 2018-09-10 |
| Weekly downloads | 0 |
| License | Apache-2.0 |
| TypeScript types | bundled |
| Module format | CommonJS |
| Dependencies | 0 |
| Unpacked size | 57.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 18 |
| Author | Blake Embrey |
| Maintainers | blakeembrey |
| Keywords | deque, fifo, lifo, queue, stack, double, linked, list, iterator, iteration |

## Links

- npm: https://www.npmjs.com/package/@blakeembrey/deque
- Repository: https://github.com/blakeembrey/deque
- Issues: https://github.com/blakeembrey/deque/issues
- npm.io page: https://npm.io/package/@blakeembrey/deque

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## Recent versions

- 1.0.5 (latest) — 2019-02-19
- 1.0.4 — 2018-11-28
- 1.0.3 — 2018-09-11
- 1.0.2 — 2018-09-11
- 1.0.1 — 2018-09-10
- 1.0.0 — 2018-09-10

## 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

---
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