JS шаблон итератор

iterator.js

var agg = (function () {
 
	var index = 0,
		data = [1, 2, 3, 4, 5],
		length = data.length;
 
	return {
 
		next:function () {
			var element;
			if (!this.hasNext()) {
				return null;
			}
			element = data[index];
			index = index + 2;
			return element;
		},
 
		hasNext:function () {
			return index < length;
		},
 
		rewind:function () {
			index = 0;
		},
 
		current:function () {
			return data[index];
		}
 
	};
}());