async+await+yield

async+await+yield.js

var generator = publishLevel(12, {data: true})

load.call(generator)

function* publishLevel(user_id, level_data) {
  var user = yield getUser(user_id)
  console.log(user)
  var can_create = yield canCreate(user)
  console.log(can_create)
  
  if (!can_create) {
    return
  }
  
  var level = yield saveLevel(user, level_data)
  
  console.log(level)
}

function getUser(user_id) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve({
        id: user_id,
        nickname: 'tlhunter'
      })
    }, 2000)
  })
}

function canCreate(user) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(user.id === 12)
    }, 1000)
  })
}

function saveLevel(user, data) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve({
        id: 100,
        owner: user.nickname,
        data: data
      });
    }, 1000)
  })
}

function load(value){
  let iterator = this.next(value)
  if (!iterator.done) {
    iterator.value.then(result => {
      load.call(this, result)
    })
  }
}