Various token issues fixed in the compiler

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 38 matching lines @@
   R visitThrow(Throw node);
   R visitTryStatement(TryStatement node);
   R visitTypeAnnotation(TypeAnnotation node);
   R visitTypedef(Typedef node);
   R visitTypeVariable(TypeVariable node);
   R visitVariableDefinitions(VariableDefinitions node);
   R visitWhile(While node);
 }
 
 Token firstBeginToken(Node first, Node second) {
-  if (first !== null) return first.getBeginToken();
-  if (second !== null) return second.getBeginToken();
-  return null;
+  var token = null;

[Lasse Reichstein Nielsen, 2012/06/27 09:22:16]

var -> Token.
Style-guide be damned!

+  if (first !== null) {
+    token = first.getBeginToken();
+  }
+  if (token === null && second !== null) {
+    // token might be null even when first is not, e.g. for empty Modifiers.

[Lasse Reichstein Nielsen, 2012/06/27 09:22:16]

Make "token" and "first" stand out here, e.g., by wrapping in [...], even if it
isn't a doc-comment.

+    token = second.getBeginToken();
+  }
+  return token;
 }
 
 class NodeAssertionFailure implements Exception {
   final Node node;
   final String message;
   NodeAssertionFailure(this.node, this.message);
 }
 
 /**
  * A node in a syntax tree.
@@ skipping 896 matching lines @@
   VariableDefinitions asVariableDefinitions() => this;
 
   accept(Visitor visitor) => visitor.visitVariableDefinitions(this);
 
   visitChildren(Visitor visitor) {
     if (type !== null) type.accept(visitor);
     if (definitions !== null) definitions.accept(visitor);
   }
 
   Token getBeginToken() {
-    return firstBeginToken(type, definitions);
+    var token = firstBeginToken(modifiers, type);
+    if (token === null) {
+      token = definitions.getBeginToken();
+    }
+    return token;
   }
 
   Token getEndToken() => endToken;
 }
 
 class Loop extends Statement {
   abstract Expression get condition();
   final Statement body;
 
   Loop(this.body);
@@ skipping 717 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);
 }