Javascript generator, simple example

generatorAccost.js

// Generator can be helpful for linearizing async logic.
// It allows you to "pause" code execution with "yield"
// and run to the next "yield" or end of generator with "next"

function* helloGen() {
  //  1:    2:
  var str = yield ' bro';
  //  3:
  console.log(str);
}

// create iterator
var it = helloGen();
// get ' bro' and pause (2)
var accost = it.next().value;
setTimeout(_ => {
  // pass into iterator 'hello, bro', that
  // will be assigned in str (1) and then
  // will be printed out in the console (3)
  it.next('hello,' + accost);  
}, 5000);