cali

Cali

A JS utility library in FP style

Installation

npm install cali

Usage

the library can be imported by AMD, CommonJS or ES6 loaders, or as the global variable 'cali'

// ES6
import * as cali from 'cali';
// CommonJS
var cali = require('cali');

API

Functions

Curry

takes a function and returns a function that's automatically curried

let curriedSum = curry((a,b,c) => a + b + c);
curriedSum(1)(2)(3) === 6; // true

Identity

takes a value and returns it

let obj = {};
identity(obj) === obj; // true

Compose

composes functions, executes each sequentially starting from the right most function

compose(a => a * 2, a => a + 1)(5) === 12

Map

maps over a collection, automatically curried

map(a => a * 2)([1,2,3]) // [2,4,6]

Functors, Applicative, Monads

Functor

general functor

let functor = new Functor(1);
functor.fmap(a => a * 2) // Functor(2)

function functor

let functor = new Functor(a => a + 1);
let f = functor.fmap(a => a * 2) // f is equivalent to 'compose(a => a + 1, a => a * 2)'
f(2) === (2 + 1) * 2

Applicative

applicative functor

let applicative = new Applicative(a => a + 1);
applicative.ap(new Applicative(2)) // Applicative(3)

Maybe

a container may have a value or nothing

Just(2).bind(x => Just(2 * x)) // Just(4)
Just(2).bind(x => Nothing).bind(x => Just(x)) // Nothing