FKit (pronounced eff-kit) is a 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 by default, so you can partially apply them wherever you need to.

• The ordering of arguments to FKit functions is carefully designed to be more natural, this makes them highly composable.

• It's very compact, roughly 3 KB when minified and gzipped!

• Getting Started
  • Node
  • Browser
• Documentation
• Examples
• Licence

Install the npm package:

> npm install fkit

Import just the functions you need:

import{add}from'fkit'console.log(add(1,2))

Or import the whole library:

import*asFfrom'fkit'console.log(F.add(1,2))

The easiest way to start using FKit in your browser is to include it with a <script> tag in your HTML file:

<scriptsrc="https://unpkg.com/fkit/dist/fkit.min.js"></script>

• API documentation

• Presentation by Josh Bassett: Everyday Functional Programming in JavaScript

• Article by Josh Bassett: Take Your Code to the Next Level with FKit

Sum the numbers in a list:

import{sum}from'fkit'sum([1,2,3])// 6

Stash a string:

import{map,surround}from'fkit'map(surround('{','}'),'hello')// '{h}{e}{l}{l}{o}'

Intersperse the numbers in a list with another number:

import{intersperse}from'fkit'intersperse(4,[1,2,3])// [1, 4, 2, 4, 3]

Filter the numbers in a list where 1 <= n <= 5:

import{between}from'fkit'[1,2,3,4,5].filter(between(2,4))// [2, 3, 4]

Calculate the Cartesian product of two lists:

import{cartesian}from'fkit'cartesian([1,2],[3,4])// [[1, 3], [1, 4], [2, 3], [2, 4]]

Calculate the permutations of a list:

import{permutations}from'fkit'permutations('abc')// ['abc', 'bac', 'cba', 'bca', 'cab', 'acb']

Check out some more examples:

• Functions
• Strings
• Arrays
• Objects
• Branching

FKit is licensed under the MIT licence. See the LICENCE file for more details.