You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

84 lines
2.3 KiB

4 years ago
[![Travis](https://img.shields.io/travis/stoeffel/compose-function.svg?style=flat-square)](https://travis-ci.org/stoeffel/compose-function)
[![npm](https://img.shields.io/npm/v/compose-function.svg?style=flat-square)](https://www.npmjs.com/package/compose-function)
[![Dependency Status](https://david-dm.org/stoeffel/compose-function.svg?style=flat-square)](https://david-dm.org/stoeffel/compose-function)
[![Coveralls](https://img.shields.io/coveralls/stoeffel/compose-function.svg?style=flat-square)](https://coveralls.io/github/stoeffel/compose-function)
<h1 align="center">Compose-Function</h1>
<p align="center">
<a href="#installation">Installation</a> |
<a href="#usage">Usage</a> |
<a href="#related">Related</a> |
<a href="#license">License</a>
<br><br>
<img align="center" height="300" src="http://33.media.tumblr.com/006dfad04f93ec5b3680ec7cdae3fafa/tumblr_n8kgl18uU41qcung4o1_1280.gif">
<br>
<sub>logo by <a href="http://justinmezzell.tumblr.com/">Justin Mezzell</a></sub>
<blockquote align="center">Compose a new function from smaller functions `f(g(x))`</blockquote>
</p>
Installation
------------
`npm install compose-function`
Usage
-----
## Basic usage
```js
import compose from 'compose-function';
const composition = compose(sqr, add2); // sqr(add2(x))
composition(2) // => 16
compose(sqr, inc)(2); // => 9
compose(inc, sqr)(2); // => 5
```
## with curry
```js
import compose from 'compose-function';
import { curry, _ } from 'curry-this';
const add = (x, y) => x + y;
// add(6, sqr(add(2, x)))
compose(
add::curry(6),
sqr,
add::curry(2),
);
// map(filter(list, even), sqr)
compose(
map::curry(_, sqr),
filter::curry(_, even),
)([1,2,3,4,5,6,7,8]) // => [4, 16, 36, 64]
```
### `::` huh?
If youre wondering what the `::` thing means, youd better read this excellent [overview](https://github.com/jussi-kalliokoski/trine/blob/5b735cbfb6b28ae94bac0446d9ecd5ce51fb149b/README.md#why) by [@jussi-kalliokoski](https://github.com/jussi-kalliokoski) or have a look at the [function bind syntax proposal](https://github.com/zenparsing/es-function-bind).
Or checkout the [curry-this docs][ct].
Related
----
* [curry-this][ct]
License
----
MIT © [Christoph Hermann](http://stoeffel.github.io)
[r]: http://ramdajs.com
[ct]: https://github.com/stoeffel/curry-this