5angel

console.log([...genFnSimple()]); // [1,2]

const [first, second] = genFnInfinite();
console.log(first); // 1
console.log(second); // 2

5angel

function* genFnInfinite() {
  let value = 0;
  while (true) {
    value++;
    yield value;
  }
}

const genObj = genFnInfinite();
console.log(genObj.next()); // { value: 1, done: false }

5angel

function* genFnSimple() {
  yield 1;
  yield 2;
  return 3;
}

for (const value of genFnSimple()) {
  console.log(value);
  // 1
  // 2

5angel

function* genFnArray() {
  yield* [1, 2, 3];
}

const genObj = genFnArray();
console.log(genObj.next());
console.log(genObj.next());
console.log(genObj.next());

5angel

const genObjA = genFnSimple();
console.log(genObjA.return()); // { value: undefined, done: true }

const genObjB = genFnSimple();
try {
  genObjA.throw(new Error('test'))
} catch (error) {
  console.log(error); // Uncaught Error: test
}

5angel

function* genFnRecursiveBad() {
  yield 0;
  const genInner = genFnSimple();
  const one = genInner.next();
  yield one.value;
  const two = genInner.next();
  yield two.value;
  const three = genInner.next();
  yield three.value;
  return 4;

5angel

function* genFnRecursive() {
  yield 0;
  const result = yield* genFnSimple();
  yield result;
  return 4;
}

const genObj = genFnRecursive();
console.log(genObj.next()); // { value: 0, done: false }
console.log(genObj.next()); // { value: 1, done: false }

5angel

function* genFnTwoWay() {
  // 0 is lost
  const received = yield 1;
  return received;
}

const genObj = genFnTwoWay();
console.log(genObj.next(0)); // { value: 1, done: false }
console.log(genObj.next(2)); // { value: 2, done: true }

5angel

function* genFnSimple() {
  yield 1;
  yield 2;
  return 3;
}

const genObj = genFnSimple();
console.log(genObj.next()); // { value: 1, done: false }
console.log(genObj.next()); // { value: 2, done: false }
console.log(genObj.next()); // { value: 3, done: true }

5angel

const asyncOptional = async (withWait) => {
  if (!withWait) {
    return true;
  }

  const result = await waitForABit(1000);
  return result;
};

const asyncTest = async () => {