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https://github.com/njlr/seq

Useful functions for manipulating JavaScript generators ⛓️
https://github.com/njlr/seq

generators javascript utility zero-dependency

Last synced: 2 months ago
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Useful functions for manipulating JavaScript generators ⛓️

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# seq

A simple library for manipulating generators and arrays in JavaScript.

[![Travis](https://img.shields.io/travis/njlr/seq.svg)](https://travis-ci.org/njlr/seq)

## Get Started

Install using [Yarn](https://yarnpkg.com/):

```bash
yarn add @njlr/seq
```

Install using [NPM](https://www.npmjs.com/):

```bash
npm install --save @njlr/seq
```

You can [browse the documentation on GitHub](https://njlr.github.io/seq/).

## Why? 🤔

* Some of the built-in Array functions are mutating (e.g. `Array.prototype.sort`).
* Many array functions are missing. Where is `Array.prototype.flatMap`?
* A chain of array functions creates a new array at every stage: the operations are not lazy.
* [lodash](https://lodash.com/) and [friends](https://github.com/jussi-kalliokoski/trine) require either a wrapper object or binding for chaining calls. We use the [pipeline operator](https://github.com/babel/babel/tree/master/packages/babel-plugin-proposal-pipeline-operator) (`|>`) to achieve this at compile-time!
* This package is a good citizen. It has no dependencies and does not mutate any global objects.
* The code is simple. You can review the whole thing in about an hour.

## Demo

```javascript
import * as seq from '@njlr/seq';

const xs = [ 1, 5, 1, 2, 7, 3, 3, 4, 5, 0 ]
|> seq.unique()
|> seq.map(x => x * 2)
|> seq.filter(x => x > 4)
|> seq.sorted()
|> seq.toArray;

// xs is [ 6, 8, 10, 14 ]
```

Since seq works on iterables, you can also use `for...of` loops:

```javascript
import * as seq from '@njlr/seq';

for (const x of seq.range(10) |> seq.map(x => x * x)) {
console.log(x);
}
```

This library also plays nicely with spread syntax!

```javascript
const squares = [ ... seq.range(10) |> seq.map(x => x * x) ];
```

## Development

Dependencies are managed by Yarn:

```bash
yarn install --pure-lockfile
```

To run all tests:

```bash
yarn test
```

To build the library:

```bash
yarn build
```

To build the documentation:

```bash
yarn docs
```

To release a new version:

```bash
npm publish --access public
```