https://www.leeboonstra.com/developer/sencha-ecmascript-2015/

ES2015-Generator-Numbers.js

function* dice () {
  while (true) {
    try {
      yield Math.floor(Math.random() * 6) + 1;
    } catch(e) {
      console.log("Error caught!");
    }
  }
}
var d = dice();

d.next(); //Object { value: 3, done: false }
d.next(); //Object { value: 6, done: false }
d.throw(new Error("Something went wrong"));
//Error caught!
//Object { value: 6, done: false }

ES2015-Generator.js

function* generator() {
  yield "image1.png"; 
  // pause
  yield "image2.png"; 
  // pause
  yield "image3.png";
  // done
}

var slides = generator();
slides.next(); //{ value: "image1.png", done: false }
slides.next(); //{ value: "image2.png", done: false }
slides.next(); //{ value: "image3.png", done: false }
slides.next(); //{ value: undefined, done: true }

for (let val of slideshow()) {
  console.log(val); //image1.png
 //image2.png
 //image3.png
}