adambene

<div class="upload-btn-wrapper">
  <button class="btn">Upload a file</button>
  <input type="file" name="myfile" />
</div>

adambene

class AlternatingArray extends Array {
  constructor(...args) {
    super(...args);
  }
  *[Symbol.iterator](){
    for (let i = 0; i < this.length; i += 2) {
      yield this[i];
    }
    for (let i = 1; i < this.length; i += 2) {
      yield this[i];

adambene

function* naturals() {
  let i = 1;
  while (true) {
    // it can count to infinity
    yield i++;
  }
}

for (let i of naturals()) {
  // count only to 5

adambene

// merge two arrays a and b
const merge = (a, b) => a.reduce(
  (acc, curr, i) => [
    ...acc, // copy all previous elements
    curr, // current element of a
    b[i] // current element of b
  ],
  [] // initial value
);

adambene

function* delays() {
  let a = yield delay(800, "Hello, I'm an");
  console.log(a);

  let b = yield delay(400, "async coroutine!");
  console.log(b);
}

// call it
coroutine()(delays());

adambene

const delay = (ms, result) =>
  new Promise(resolve => setTimeout(() => resolve(result), ms));

adambene

function delays() {
  return delay(800, "Hello, I'm in a").then(a => {
    console.log(a);
    return delay(400, "Promise!");
  }).then(b => {
    console.log(b);
  });
}

// call it

adambene

const delay = (ms, result, cb) => setTimeout(() => cb(result), ms);

function delays() {
  delay(800, "Hello, I'm in a", a => {
    console.log(a);
    delay(400, "callback!", b => {
      console.log(b);
    });
  });
}

adambene

const coroutine = nextValue => iterator => {
  const { done, value } = iterator.next(nextValue);

  if (done) {
    return;
  }

  if (value.constructor === Promise) {
    value.then(promiseValue => {
      coroutine(promiseValue)(iterator);

adambene

async function delays() {
  let a = await delay(800, "Hello, I'm in an");
  console.log(a);

  let b = await delay(400, "async function!");
  console.log(b);
}

delays();