dart2dart: Implementation of simple try/catch.

pkg/compiler/lib/src/dart_backend/backend_ast_nodes.dart

 // Copyright (c) 2014, 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.
 
 library backend_ast_nodes;
 
 import '../constants/values.dart' as values;
 import '../dart_types.dart' as types;
 import '../elements/elements.dart' as elements;
 import '../tree/tree.dart' as tree;
@@ skipping 189 matching lines @@
   final List<CatchBlock> catchBlocks;
   final Statement finallyBlock;
 
   Try(this.tryBlock, this.catchBlocks, [this.finallyBlock]) {
     assert(catchBlocks.length > 0 || finallyBlock != null);
   }
 }
 
 class CatchBlock extends Node {
   final TypeAnnotation onType;
-  final String exceptionVar;
-  final String stackVar;
+  final VariableDeclaration exceptionVar;
+  final VariableDeclaration stackVar;
   final Statement body;
 
   /// At least onType or exceptionVar must be given.
   /// stackVar may only be given if exceptionVar is also given.
   CatchBlock(this.body, {this.onType, this.exceptionVar, this.stackVar}) {
     // Must specify at least a type or an exception binding.
     assert(onType != null || exceptionVar != null);
 
     // We cannot bind the stack trace without binding the exception too.
     assert(stackVar == null || exceptionVar != null);
@@ skipping 981 matching lines @@
     } else if (stmt is Try) {
       write('try');
       writeBlock(stmt.tryBlock);
       for (CatchBlock block in stmt.catchBlocks) {
         if (block.onType != null) {
           write('on ');
           writeType(block.onType);
         }
         if (block.exceptionVar != null) {
           write('catch(');
-          write(block.exceptionVar);
+          write(block.exceptionVar.name);
           if (block.stackVar != null) {
             write(',');
-            write(block.stackVar);
+            write(block.stackVar.name);
           }
           write(')');
         }
         writeBlock(block.body);
       }
       if (stmt.finallyBlock != null) {
         write('finally');
         writeBlock(stmt.finallyBlock);
       }
     } else if (stmt is VariableDeclarations) {
@@ skipping 343 matching lines @@
   final StringChunk previous;
   final tree.StringQuoting quoting;
   num cost;
 
   OpenStringChunk(this.previous, this.quoting, this.cost);
 
   StringChunk end(int endIndex) {
     return new StringChunk(previous, quoting, endIndex);
   }
 }