Rework Unparser/unparse StringBuffer management.

lib/compiler/implementation/tree/nodes.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 Visitor<R> {
   R visitBlock(Block node);
   R visitBreakStatement(BreakStatement node);
   R visitCascade(Cascade node);
   R visitCascadeReceiver(CascadeReceiver node);
   R visitCaseMatch(CaseMatch node);
@@ skipping 81 matching lines @@
 
   hashCode() => _hashCode;
 
   abstract accept(Visitor visitor);
 
   abstract visitChildren(Visitor visitor);
 
   /**
    * Returns this node unparsed to Dart source string.
    */
-  toString() => unparse();
+  toString() => unparse(this);
 
   /**
    * Returns Xml-like tree representation of this node.
    */
   toDebugString() {
     return PrettyPrinter.prettyPrint(this);
   }
 
   String getObjectDescription() => super.toString();
 
-  String unparse() {
-    Unparser unparser = new Unparser();
-    try {
-      return unparser.unparse(this);
-    } catch (e, trace) {

[ahe, 2012/09/18 13:29:18]

Why was this removed?

I'm looking at this stack trace right now:

<Received error while converting exception to string>
#0      Object._noSuchMethod (dart:core-patch:2496:3)
#1      Object.noSuchMethod (dart:core-patch:2493:18)
#2      Dart2JsLibraryMirror.simpleName
(file:///Users/ahe/Dart/all/dart/pkg/dartdoc/lib/src/mirrors/dart2js_mirror.dart:495:42)
#3      Dart2JsLibraryMirror.canonicalName
(file:///Users/ahe/Dart/all/dart/pkg/dartdoc/lib/src/mirrors/dart2js_mirror.dart:486:41)
#4      Dart2JsMirrorSystem._ensureLibraries.<anonymous closure>
(file:///Users/ahe/Dart/all/dart/pkg/dartdoc/lib/src/mirrors/dart2js_mirror.dart:442:40)
#5      HashMapImplementation.forEach (bootstrap_impl:914:10)
#6      Dart2JsMirrorSystem._ensureLibraries
(file:///Users/ahe/Dart/all/dart/pkg/dartdoc/lib/src/mirrors/dart2js_mirror.dart:440:33)
#7      Dart2JsMirrorSystem.libraries
(file:///Users/ahe/Dart/all/dart/pkg/dartdoc/lib/src/mirrors/dart2js_mirror.dart:449:21)
#8      HtmlDiff.run
(file:///Users/ahe/Dart/all/dart/utils/apidoc/html_diff.dart:95:58)
#9      main (file:///Users/ahe/Dart/all/dart/utils/apidoc/apidoc.dart:85:12)

If this code had been in place, I would have the information I need to debug and
implement library syntax.

[Anton Muhin, 2012/09/19 09:38:43]

Sorry, I don't immediately see what's the problem: apparently there is no
exception thrown while unparsing.

On 2012/09/18 13:29:18, ahe wrote:

[ahe, 2012/09/19 10:33:12]

The code is there to handle when something that isn't tested breaks. For
example, when we add a new subclass of Node.

-      print(trace);
-      return '<<unparse error: ${getObjectDescription()}: ${unparser.sb}>>';
-    }
-  }
-
   abstract Token getBeginToken();
 
   abstract Token getEndToken();
 
   Block asBlock() => null;
   BreakStatement asBreakStatement() => null;
   Cascade asCascade() => null;
   CascadeReceiver asCascadeReceiver() => null;
   CaseMatch asCaseMatch() => null;
   CatchBlock asCatchBlock() => null;
@@ skipping 1628 matching lines @@
  * argument).
  *
  * TODO(ahe): This method is controversial, the team needs to discuss
  * if top-level methods are acceptable and what naming conventions to
  * use.
  */
 initializerDo(Node node, f(Node node)) {
   SendSet send = node.asSendSet();
   if (send !== null) return f(send.arguments.head);
 }