Properly unparse sequences like x + +1 and x - -1.

lib/compiler/implementation/tree/unparser.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.
 
 // Returns null if no need to rename a node.
 typedef String Renamer(Node node);
 
 String unparse(Node node) {
   Unparser unparser = new Unparser();
   unparser.unparse(node);
@@ skipping 261 matching lines @@
       } else if (node.selector.asOperator() === null) {
         sb.add('.');
       } else if (spacesNeeded) {
         sb.add(' ');
       }
     }
   }
 
   visitSend(Send node) {
     Operator op = node.selector.asOperator();
-    bool spacesNeeded = op !== null &&
-        (op.source.stringValue === 'is' || op.source.stringValue == 'as');
+    String opString = op !== null ? op.source.stringValue : null;
+    bool spacesNeeded = opString === 'is' || opString === 'as';
 
     if (node.isPrefix) visit(node.selector);
     unparseSendReceiver(node, spacesNeeded: spacesNeeded);
     if (!node.isPrefix && !node.isIndex) visit(node.selector);
     if (spacesNeeded) sb.add(' ');
+    // Also add a space for sequences like x + +1 and y - -y.
+    if (opString === '-' || opString === '+') {
+      Token beginToken = node.argumentsNode.getBeginToken();
+      if (beginToken !== null && beginToken.stringValue === opString) sb.add(' ');

[Roman, 2012/10/02 13:22:24]

80 chars

+    }
     visit(node.argumentsNode);
   }
 
   visitSendSet(SendSet node) {
     if (node.isPrefix) {
       sb.add(' ');
       visit(node.assignmentOperator);
     }
     unparseSendReceiver(node);
     if (node.isIndex) {
@@ skipping 252 matching lines @@
     add(node.getEndToken().value);
   }
 
   visitPartOf(PartOf node) {
     addToken(node.partKeyword);
     addToken(node.ofKeyword);
     visit(node.name);
     add(node.getEndToken().value);
   }
 }