asbjornh / kompis

kompis

A collection of plain and higher order functions for doing composition stuff in javascript.

Documentation

Usage

npm install kompis

All exports are named. Example:

import { Pipe, map, add } from "kompis";
Pipe(map(add(10)));

// You can also do:
import * as K from "kompis";
K.Pipe(K.map(K.add(10)));

ES6

ES6 source can be imported from kompis/es6 (it's about a third of the size of the regular ES5 version).

About

The functions can be divided in two groups: core functions and utils. The utils are properly documented below. The core functions are all pretty small so their implementations are included (without further documentation) at the bottom of this readme.

Argument order

Higher order functions that accept more than one thing accept the data to operate on last (opposite of native js counerparts). This makes partial application more practical.

// Vanilla javascript (data first)
"A".padStart(3, "_"); // "__A"
[1, 2, 3].map(n => n + 1); // [2, 3, 4]

// 'padStart' and 'map' from this package (data last)
padStart(3, "_")("A"); // "__A"
map(add(1))([1, 2, 3]); // [2, 3, 4]

Note: this also applies to math functions like subtract and divide:

// Vanilla javascript
2 / 4; // 0.5

// 'divide' from this package
const divideByTwo = divide(2);
divideByTwo(4); // 2
divide(2)(4); // also 2

kompis's Issues

Add typescript definitions?

For better intellisense

Add label option to `trace`

trace("blabla:")(1); // logs "blabla: 1"

mapIf

const mapIf = (predicate, ifFunc, elseFunc) => v =>
  predicate(v) ? ifFunc(v) : elseFunc(v);