Support for stack traces in catch blocks.

frog/leg/tree/nodes.dart

 // Copyright (c) 2011, 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 Visitor<R> {
   R visitBlock(Block node);
   R visitBreakStatement(BreakStatement node);
   R visitCatchBlock(CatchBlock node);
   R visitClassNode(ClassNode node);
   R visitConditional(Conditional node);
@@ skipping 1642 matching lines @@
   final Block block;
 
   final catchKeyword;
 
   CatchBlock(this.formals, this.block, this.catchKeyword);
 
   CatchBlock asCatchBlock() => this;
 
   accept(Visitor visitor) => visitor.visitCatchBlock(this);
 
+  Node get exception() {
+    if (formals.nodes.isEmpty()) return null;

[ahe, 2012/03/06 12:24:07]

Perhaps you should check if this returns null in the resolver.

[ngeoffray, 2012/03/06 12:29:40]

It's already doing it.

+    VariableDefinitions declarations = formals.nodes.head;
+    return declarations.definitions.nodes.head;
+  }
+
+  Node get trace() {
+    if (formals.nodes.isEmpty()) return null;
+    Link<VariableDefinitions> declarations = formals.nodes.tail;
+    return declarations.isEmpty()
+        ? null
+        : declarations.head.definitions.nodes.head;
+  }
+
   visitChildren(Visitor visitor) {
     formals.accept(visitor);
     block.accept(visitor);
   }
 
   Token getBeginToken() => catchKeyword;
 
   Token getEndToken() => block.getEndToken();
 }
 
@@ skipping 11 matching lines @@
   static bool isConstructorRedirect(Send node) {
     return (node.receiver === null &&
             node.selector.asIdentifier() !== null &&
             node.selector.asIdentifier().isThis()) ||
            (node.receiver !== null &&
             node.receiver.asIdentifier() !== null &&
             node.receiver.asIdentifier().isThis() &&
             node.selector.asIdentifier() !== null);
   }
 }