生成器与Promise

[dp9u0]

• yield
• yield and promise

[dp9u0]

function* foo() {
  let x = 2 + (yield 0);
  let y = yield 1;
  let z = yield 2;
  console.log({
    x,
    y,
    z
  })
}
let it = foo();
console.log(it.next(1));
console.log(it.next(2));
console.log(it.next(3));
console.log(it.next(4));

{ value: 0, done: false }
{ value: 1, done: false }
{ value: 2, done: false }
{ x: 4, y: 3, z: 4 }
{ value: undefined, done: true }