Function to synchronize an asynchronous sets of operations (gotten from Node.js Design Patterns)

asyncflow.js

function isGenerator(obj) {
    return 'function' == typeof obj.next && 'function' == typeof obj.throw;
}


function isGeneratorFunction(obj) {
    var constructor = obj.constructor;
    if (!constructor) return false;
    if ('GeneratorFunction' === constructor.name || 'GeneratorFunction' === constructor.displayName) return true;
    return isGenerator(constructor.prototype);
  }
  

module.exports = function asyncFlow(generatorFunction) {

    if(!isGeneratorFunction(generatorFunction))
    {
        throw new Error('paramter not a generator function');
    }

	var generator = generatorFunction(callback);
    generator.next();
    
    
    
	function callback(err) {
		if (err) {
			return generator.throw (err);
		}
		var results = [].slice.call(arguments, 1);
		generator.next(results.length > 1 ? results : results[0]);
	};
}