Taming callbacks with generators

betterAsync.js

'use strict'

// you need to use iojs for this... or something

function async(myGenerator){
	return function(){
		
		var theGenerator = myGenerator.apply(this, arguments);

		function handle(result){
			//console.log('handling...')
			//console.log(result)
			
			if (result.done){
				//console.log("!")
				return Promise.resolve(result.value);
			}
			
			//console.log("result value ---> ");
			//console.log(result.value);

			return Promise
				.resolve(result.value)
				.then(function(res){
					//console.log('#')
					handle(theGenerator.next(res))
				}, function(err){
					//console.log('!!')
					handle(theGenerator.throw(err))
				});
		}

		try {
			console.log('start...')
	      	return handle(theGenerator.next());
	    } catch (ex) {
	      return Promise.reject(ex);
	    }

	};
}

var hello = function(){
	return new Promise(function(resolve, reject){
		setTimeout(function(){
			resolve("hello")
		}, 1500);
	});
}

var world = function(){
	return new Promise(function(resolve, reject){
		setTimeout(function(){
			resolve("world")
		}, 1000);
	});
}

var l = async(function* (){
	
	var h = yield hello();
	var w = yield world();

	console.log("=> " + h + " " + w);
});


l();

//console.log(g.next(200))
//console.log(g.next(200))