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FKit (pronounced eff-kit) is a [functional
programming](http://en.wikipedia.org/wiki/Functional_programming) toolkit for
JavaScript. It provides many functions for solving common problems with
functions, objects, arrays, and strings. It aims to provide reusable building
blocks while maintaining a laser focus on everyday utility.
Features:
* Why reinvent the wheel? FKit provides many functions for solving everyday
problems to do with functions, arrays, objects, and strings.
* FKit treats both strings and arrays as *lists*, which means you can apply the
same list functions to both strings and arrays (e.g. `head`, `tail`, `map`,
`filter`, `fold`, etc).
* Most FKit functions are already
[curried](http://en.wikipedia.org/wiki/Currying) by default, so you can
[partially apply](http://en.wikipedia.org/wiki/Partial_application) them
wherever you need to.
* The ordering of arguments to FKit functions is carefully designed to be more
natural, this makes them highly
[composable](http://en.wikipedia.org/wiki/Function_composition).
* It's very compact, roughly 3 KB when minified and gzipped!
## Table of Contents
* [Getting Started](#getting-started)
* [Node](#node)
* [Browser](#browser)
* [Documentation](#documentation)
* [Examples](#examples)
* [Licence](#licence)
## Getting Started
### Node
Install the npm package:
```sh
> npm install fkit
```
Import just the functions you need:
```js
import { add } from 'fkit'
console.log(add(1, 2))
```
Or import the whole library:
```js
import * as F from 'fkit'
console.log(F.add(1, 2))
```
### Browser
The easiest way to start using FKit in your browser is to include it with a
`
```
## Documentation
* [API documentation](http://fkit.joshbassett.info/)
* Presentation by Josh Bassett: [Everyday Functional Programming in
JavaScript](https://speakerdeck.com/nullobject/fkit-everyday-functional-programming-in-javascript)
* Article by Josh Bassett: [Take Your Code to the Next Level with
FKit](http://joshbassett.info/2014/take-your-code-to-the-next-level-with-fkit/)
## Examples
Sum the numbers in a list:
```js
import { sum } from 'fkit'
sum([1, 2, 3]) // 6
```
Stash a string:
```js
import { map, surround } from 'fkit'
map(surround('{', '}'), 'hello') // '{h}{e}{l}{l}{o}'
```
Intersperse the numbers in a list with another number:
```js
import { intersperse } from 'fkit'
intersperse(4, [1, 2, 3]) // [1, 4, 2, 4, 3]
```
Filter the numbers in a list where 1 <= n <= 5:
```js
import { between } from 'fkit'
[1, 2, 3, 4, 5].filter(between(2, 4)) // [2, 3, 4]
```
Calculate the Cartesian product of two lists:
```js
import { cartesian } from 'fkit'
cartesian([1, 2], [3, 4]) // [[1, 3], [1, 4], [2, 3], [2, 4]]
```
Calculate the permutations of a list:
```js
import { permutations } from 'fkit'
permutations('abc') // ['abc', 'bac', 'cba', 'bca', 'cab', 'acb']
```
Check out some more examples:
* [Functions](http://codepen.io/nullobject/pen/dbAkl?editors=001)
* [Strings](http://codepen.io/nullobject/pen/hnDEe?editors=001)
* [Arrays](http://codepen.io/nullobject/pen/vbcCr?editors=001)
* [Objects](http://codepen.io/nullobject/pen/rKszh?editors=001)
* [Branching](http://codepen.io/nullobject/pen/LdtDK?editors=001)
## Licence
FKit is licensed under the MIT licence. See the
[LICENCE](https://github.com/nullobject/fkit/blob/master/LICENCE.md) file for
more details.