Cases in a switch introduce a new scope.

frog/leg/resolver.dart

 // Copyright (c) 2012, 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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
 }
 
 class TreeElementMapping implements TreeElements {
@@ skipping 1143 matching lines @@
     node.expression.accept(this);
     StatementElement element = getOrCreateStatementElement(node);
     statementScope.enterLoop(element);
     node.cases.accept(this);
     statementScope.exitLoop();
   }
 
   visitSwitchCase(SwitchCase node) {
     // TODO(ahe): What about the label?
     node.expression.accept(this);
-    node.statements.accept(this);
+    visitIn(node.statements, new BlockScope(context));

[ahe, 2012/03/07 22:24:15]

I can't find this in the specification.

[ngeoffray, 2012/03/07 22:31:11]

We have a test for it SwitchScopeTest. And the JSON implementation of dart
assumes there is a new scope. Ergo, spec forgot to mention it :)

[ahe, 2012/04/13 13:50:19]

Then you need to file a specification bug.

[ngeoffray, 2012/04/16 13:49:35]

Yes: http://code.google.com/p/dart/issues/detail?id=2057

[ahe, 2012/04/16 14:51:58]

Thank you. Starred it :-)

   }
 
   visitDefaultCase(DefaultCase node) {
     // TODO(ahe): What about the label?
-    node.statements.accept(this);
+    visitIn(node.statements, new BlockScope(context));
   }
 
   visitTryStatement(TryStatement node) {
     visit(node.tryBlock);
     if (node.catchBlocks.isEmpty() && node.finallyBlock == null) {
       // TODO(ngeoffray): The precise location is
       // node.getEndtoken.next. Adjust when issue #1581 is fixed.
       error(node, MessageKind.NO_CATCH_NOR_FINALLY);
     }
     visit(node.catchBlocks);
@@ skipping 312 matching lines @@
 class TopScope extends Scope {
   LibraryElement get library() => element;
 
   TopScope(LibraryElement library) : super(null, library);
   Element lookup(SourceString name) => library.find(name);
 
   Element add(Element element) {
     throw "Cannot add an element in the top scope";
   }
 }