Reducing the amount of code we generate in the compiler: We still continue

lib/src/analyzer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Part of the template compilation that concerns with extracting information
  * from the HTML parse tree.
  */
 library analyzer;
 
@@ skipping 92 matching lines @@
     if (node.tagName == 'style') {
       // We've already parsed the CSS.
       // If this is a component remove the style node.
       if (_currentInfo is ComponentInfo) node.remove();
       return;
     }
 
     node = _bindAndReplaceElement(node);
 
     var lastInfo = _currentInfo;
-    if (node.tagName == 'element') {
+    if (node.tagName == 'polymer-element') {
       // If element is invalid _ElementLoader already reported an error, but
       // we skip the body of the element here.
       var name = node.attributes['name'];
       if (name == null) return;
 
       ComponentInfo component = _fileInfo.components[name];
       if (component == null) return;
 
-      // Associate <element> tag with its component.
-      component.elementNode = node;
-
       _analyzeComponent(component);
 
       _currentInfo = component;
 
       // Remove the <element> tag from the tree
       node.remove();
     }
 
     node.attributes.forEach((name, value) {
       if (name.startsWith('on')) {
@@ skipping 68 matching lines @@
     if (component == null) {
       // TODO(jmesserly): warn for unknown element tags?
 
       // <button is="fancy-button">
       var componentName = node.attributes['is'];
       if (componentName != null) {
         component = _fileInfo.components[componentName];
       } else if (isCustomTag(node.tagName)) {
         componentName = node.tagName;
       }
-      if (component == null && componentName != null) {
+      if (component == null && componentName != null &&
+          componentName != 'polymer-element') {
         _messages.warning(
             'custom element with tag name $componentName not found.',
             node.sourceSpan);
       }
     }
     if (component != null && !component.hasConflict) {
       _currentInfo.usedComponents[component] = true;
       return component;
     }
     return null;
@@ skipping 141 matching lines @@
    * must not be null.
    */
   _ElementLoader(this._global, this._fileInfo, this._packageRoot,
       this._messages) {
     _currentInfo = _fileInfo;
   }
 
   void visitElement(Element node) {
     switch (node.tagName) {
       case 'link': visitLinkElement(node); break;
-      case 'element': visitElementElement(node); break;
+      case 'element':
+        _messages.warning('<element> elements are not supported, use'
+            ' <polymer-element> instead', node.sourceSpan);
+        break;
+      case 'polymer-element':
+         visitElementElement(node);
+         break;
       case 'script': visitScriptElement(node); break;
       case 'head':
         var savedInHead = _inHead;
         _inHead = true;
         super.visitElement(node);
         _inHead = savedInHead;
         break;
       default: super.visitElement(node); break;
     }
   }
@@ skipping 333 matching lines @@
               }
             }
           }
         }
       }
     }
 
     return seen;
   }
 }