deepCopy.js

deepCopyItem = function(item) {
	var listProto = Object.prototype.toString.call([]);
	var objectProto = Object.prototype.toString.call({});
	var itemProto = Object.prototype.toString.call(item);
	if (itemProto != listProto && itemProto != objectProto) {
		console.warn("Cannot create a deep copy from " + itemProto);
		return undefined;
	}
	
	var newItem = function() {
		if (itemProto === listProto) return [];
		else return {};
	}();
	var newItemProto = Object.prototype.toString.call(newItem);

	for (var itemIndex in item) {
		var itemValue = item[itemIndex];
		var itemValueProto = Object.prototype.toString.call(itemValue);
		var newValue;
		
		if (itemValueProto === listProto) {
			newValue = deepCopyItem(itemValue);
		} else if (itemValueProto === objectProto) {
			newValue = deepCopyItem(itemValue);
		} else {
			newValue = itemValue;
		}
		
		if (newItemProto === listProto) newItem.push(newValue);
		else newItem[itemIndex] = newValue;
	}
	
	return newItem;
};