feat(router): implement RouterUrlParser

modules/angular2/src/alt_router/router_url_parser.ts

@@ -0,0 +1,27 @@
+import {UrlSegment, Tree} from './segments';
+import {BaseException} from 'angular2/src/facade/exceptions';
+
+export abstract class RouterUrlParser { abstract parse(url: string): Tree<UrlSegment>; }
+
+export class DefaultRouterUrlParser extends RouterUrlParser {
+  parse(url: string): Tree<UrlSegment> {
+    if (url.length === 0) {
+      throw new BaseException(`Invalid url '${url}'`);
+    }
+    return new Tree<UrlSegment>(this._parseNodes(url));
+  }
+
+  private _parseNodes(url: string): UrlSegment[] {
+    let index = url.indexOf("/", 1);
+    let children: UrlSegment[];
+    let currentUrl;
+    if (index > -1) {
+      children = this._parseNodes(url.substring(index + 1));
+      currentUrl = url.substring(0, index);
+    } else {
+      children = [];
+      currentUrl = url;
+    }
+    return [new UrlSegment(currentUrl, {}, "")].concat(children);
+  }
+}