untitled.js

window.console = skewer

var createCounter = (startVal = 0) => {
  let state = startVal
  return {
    next: () => {
      if(state < (10 + startVal))
        return {value: state+=1}
      return {done: true}
    }
  }
}

var counter = createCounter(5)
var {done, value} = counter.next()
while(!done) {
  console.log(value)
  const x = counter.next()
  done = x.done
  value = x.value
}