async-co

Control flow for ES6 generator (co) with async.js (v2) signatures

Motivation

async-co provide javascript async/await (through ES6 generator & co) equivalent signatures of the excellent async workflow library.

Addition to the async library signatures

Because of the Promise contract (and sane API), it's easy to "throttle" a function that return a Promise (see the "throttle" API, for a way to make an ultra simple http request pooling).

API

async-co/eachLimit(arr, concurrency, *thunk)

Nothing special here

async-co/eachSeries(arr, *thunk)

// = eachLimit concurrency = 1

async-co/each(arr, *thunk)

// = eachLimit concurrency = arr.length

async-co/eachOfLimit (dict, concurrency, *thunk)

Nothing special here neither

async-co/eachOfSeries(dict, *thunk)

// = eachOfLimit concurrency = 1

async-co/eachOf(dict, *thunk)

// = eachOfLimit concurrency = dict.length

const eachLimit    = require('async-co/eachLimit');

co(function *() {

  var stuffs = [1,2,3, 5, 7]

  yield eachLimit(stuffs, 2, function*(id){
      yield dootherStuffs(id);
  });

});

q = async-co/queue(*thunk, concurrency)

Return a QueueObject you can push task into.

yield q.push(task)

Wait for thunk to process task (wait for worker, if needed)

const queue    = require('async-co/queue');
const fetch    = require('node-fetch');

var q = queue(fetch, 1); //let's be nice

co(function *() {
  yield q.push("http://example.com/stuff.json");
});

co(function *() {
  yield q.push("http://example.com/otherstuff.json"); //will wait for stuff to be retrieved
});

async-co/throttle

Throttle any function that return a promise, sugar syntax helper for async-co/queue

const throttle = require('async-co/throttle');
var  fetch     = require('node-fetch');
fetch = throttle(fetch, 1); //make fetch behave nicely

co(function *() {
  yield fetch("http://example.com/stuff.json");
});

co(function *() {
  yield fetch("http://example.com/otherstuff.json"); //will wait for stuff.json to be retrieved
});

TODO

• Get rich or die tryin'

Credits

• 131
• not dependant upon, yet relying on co
• inspired from the excellent async

Shoutbox, keywords, SEO love

async/await, ES6 generators, co, async-co, promise, Promises, yield, async, queue, map, throttle, "Let's have a beer & talk in Paris"