Useful oneliners and shorthand functions

Usage no npm install needed!

<script type="module">
  import Liners from 'https://cdn.skypack.dev/1-liners';



Coverage Status Build Status Dependency Status npm version Stability: unstable Join the chat at https://gitter.im/1-liners/1-liners


Functional tools that couldn’t be simpler.

We’re proud to present 1-liners – a dead simple functional utility belt. 137 one-liner functions (and counting). Each hand-crafted with love and attention.

Our decalogue

You get a product of top-quality functional programming craftmanship. Each function follows the KISS principle, which we’ve broken down into ten strict rules.

We always follow them. You have our word.


  1. Each function shall fit in one readable line of code
    – take a glimpse at the source and you know exactly what’s going on.

  2. Each function shall have no side-effects
    – you can use it with confidence.

  3. Each function shall have a fixed number of arguments
    – it’s dead easy to bind, curry and uncurry, apply partially, implode and explode.

  4. Each function shall deal with data in an immutable way
    – no more debugging nightmares.

  5. Each function shall take data as the last argument
    – this makes currying and composing new functions a breeze.

  6. Each function shall be in a separate micro-module
    – you only load/bundle the single 1-liner you need.

  7. Each function shall be thoroughly tested
    – 100% code coverage guaranteed. We even test if every function fits in one line!

  8. Each function shall have great documentation
    – the docs explain usage, present the source, and link to the specs.

  9. We shall provide functional versions of native object methods
    – like reduce(callback, array) for array.reduce(callback).

  10. We shall provide functional versions of language constructs
    – like plus(a, b) for a + b.



$ npm install --save 1-liners

Usage in ES5

// The lightweight, recommended way:
var map = require('1-liners/map');

// Sometimes practical:
var map = require('1-liners').map;

Usage in ES 2015 (formerly ES6)

// The lightweight, recommended way:
import map from '1-liners/module/map';

// Sometimes practical:
import { map, filter } from '1-liners/module';


Checkout the documentation


stoeffel tomekwi hemanth
stoeffel tomekwi hemanth
davidchase tristaaan
davidchase tristaaan

created with gh-contributors-table


MIT © stoeffel tomekwi hemanth davidchase tristaaan