Support for stack traces in catch blocks.

frog/leg/tree/nodes.dart

Index: frog/leg/tree/nodes.dart
===================================================================
--- frog/leg/tree/nodes.dart	(revision 4945)
+++ frog/leg/tree/nodes.dart	(working copy)
@@ -1591,6 +1591,18 @@
 
   accept(Visitor visitor) => visitor.visitCatchBlock(this);
 
+  Node get exception() {
+    VariableDefinitions declarations = formals.nodes.head;

[ahe, 2012/03/06 08:44:22]

This may be null. The parser accepts:

try {} catch () {}

[ngeoffray, 2012/03/06 12:12:50]

Done.

+    return declarations.definitions.nodes.head;
+  }
+
+  Node get trace() {
+    Link<VariableDefinitions> declarations = formals.nodes.tail;

[ahe, 2012/03/06 08:44:22]

See comment above.

[ngeoffray, 2012/03/06 12:12:50]

Done.

+    return declarations.isEmpty()
+        ? null
+        : declarations.head.definitions.nodes.head;
+  }
+
   visitChildren(Visitor visitor) {
     formals.accept(visitor);
     block.accept(visitor);