Swift - DOM implementation

dom.swift

import cocoa;
// Base DOM interface
protocol Node {
    var childNodes: [AnyObject]{get set};
    var nodeName: NodeType{get set};
}

enum NodeType {
    case Text(String)
    case Element(ElementData)
}

struct ElementData {
    var tag_name: String;
    var attributes:  [String: String];
}


// Our HTML superset
class HTMLElement:Node {
    var attributes = [String: String]();
    var childNodes: [AnyObject] = [HTMLElement]();
    var nodeName: NodeType;
    
    func addAttribute(name:String, value:String) {
        attributes[name] = value;
    }
    
    func appendChild(newNode: HTMLElement) {
        childNodes.append(newNode);
    }
    
    init() {
        nodeName = NodeType.Element(ElementData(tag_name: "HTMLElement", attributes: self.attributes));
    }
}

class HTMLDivElement:HTMLElement {
    override init() {
        super.init();
        nodeName = NodeType.Element(ElementData(tag_name: "HTMLDivElement", attributes: self.attributes));
    }
}


// DOM API
class Document {
    var body = HTMLElement();
    init() {
    }
    func createElement(tagName: String) -> HTMLElement {
        switch(tagName) {
            case "HTMLDivElement":
                return HTMLDivElement();
            default:
                return HTMLElement();
        }
    }
}



var document = Document();
// create new div
var exampleDiv = document.createElement("HTMLDivElement");
exampleDiv.addAttribute("id", value: "div 1");
var exampleDiv2 = document.createElement("HTMLDivElement");
exampleDiv2.addAttribute("id", value: "div 2");

// append to body
document.body.appendChild(exampleDiv);
document.body.appendChild(exampleDiv2);

// sub div
var subDiv = document.createElement("HTMLDivElement");
subDiv.addAttribute("id", value: "subDiv 1");

// insert in example div
exampleDiv.appendChild(subDiv);


print(document.body.childNodes.count);
print(exampleDiv.attributes);
print(exampleDiv.childNodes.count);
print((exampleDiv.childNodes[0] as! HTMLDivElement).attributes);
print(exampleDiv2.attributes);