async/await by generator

agen-sample.js

function wait(msec){
	return new Promise((resolve, reject) => {
		setTimeout(resolve, msec)
	})
}

function* async_sample(val){
	yield wait(1000)
	console.log("after 1second")
	console.log(val)
}

async_sample.async("abc")

agen.js

;(function*(){}).constructor.prototype.async = function(...args){
	return new Promise((resolve, reject) => {
		var ite = this(...args)
		!function recur(pre_value){
			var ret = ite.next(pre_value)
			ret.done ? resolve(ret.value) : ret.value.then(recur)
		}()
	})
}