throttle.js

function unthrottle(it){
	cancelAnimationFrame(it.index);
	it.node.removeEventListener(it.type, it.throttle);
	
	return it;
}
/**
 * @param {object} it defines what to throttle, requires 3 properties:
 * @param {string} it.type event name
 * @param {Node} it.node DOM element
 * @param {function} it.handler event-handler attached to node for event
 */
function throttle(it){
	it.index = it.time = 0;
	it.event = {};
	it.relay = function(time){
		var _ = it, t = (time - _.time).toFixed(0);
		_.time = time;
		console.log('relay',_.type,t);
		// behave like a standard event-handler
		_.handler.call(_.node, _.event);
		_.event = {};
	};
	it.throttle = function _relay(event){
		var _ = it;
		_.event = event;
		cancelAnimationFrame(_.index);
		_.index = requestAnimationFrame(_.relay);
	};
	it.node.addEventListener(it.type, it.throttle);

	return it;
}

throttle({type:'scroll', node:window, handler: function(event){
	console.log(event.type, event, this);
}});