GitHub - DrBoolean/immutable-ext: fantasyland extensions for immutablejs (original) (raw)

immutable-ext

fantasyland extensions for immutablejs

Install

npm install immutable-ext

What is this?

In addition to the Functor, Foldable, and Monad functions, we now have:

• Monoid
• Applicative (list only right now)
• Traversable

Plus stuff that builds off of reduce like foldMap. Please contribute/complain as you want/need things.

Examples

We can now traverse without messing with Array or Object:

const { List, Map } = require('immutable-ext') const Task = require('data.task') const IO = require('fantasy-io')

// Given Http.get :: String -> Task Error Blog

List.of('/blog/1', '/blog/2') .traverse(Task.of, Http.get) .fork(console.error, console.log) // List(Blog, Blog)

Map({home: "

ask me anything

// IO(Map({home: "[dom]", faq: "[dom]"})

We can fold stuff down

const {Disjunction, Additive} = require('fantasy-monoids')

List.of([1,2,3], [4,5,6]).fold([]) //[1,2,3,4,5,6]

Map({a: "hidy", b: "hidy", c: "ho"}).fold("") // "hidyhidyho"

List.of(Map({a: Additive(1), b: Disjunction(true), c: "son", d: [1], e: 'wut'}), Map({a: Additive(2), b: Disjunction(false), c: "ofa", d: [2]}), Map({a: Additive(3), b: Disjunction(false), c: "gun", d: [3]})).fold(Map.empty),

// Map({a: Additive(6), b: Disjunction(true), c: "sonofagun", d: [1,2,3], e: 'wut'})))

foldMap some things

List.of(1,2,3,4).foldMap(Additive, Additive.empty) // Additive(10)

Map({a: true, b: false}).foldMap(Disjunction, Disjunction.empty) // Disjunction(true)

We can ap to get us some list comprehensions

List.of(x => y => x + y) .ap(List.of('a', 'b', 'c')) .ap(List.of('+', '-'))

// List('a+', 'a-', 'b+', 'b-', 'c+', 'c-')