dart2dart: Method and constructor calls in new backend.

sdk/lib/_internal/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.
 
 part of tree;
 
 String unparse(Node node) {
   Unparser unparser = new Unparser();
   unparser.unparse(node);
   return unparser.result;
@@ skipping 283 matching lines @@
     } else if (spacesNeeded) {
       sb.write(' ');
     }
   }
 
   visitSend(Send node) {
     Operator op = node.selector.asOperator();
     String opString = op != null ? op.source : null;
     bool spacesNeeded = identical(opString, 'is') || identical(opString, 'as');
 
-    if (node.isPrefix) visit(node.selector);
+    if (node.isPrefix) {
+      visit(node.selector);
+      // Add a space for sequences like - -x (double unary minus).
+      if (identical(opString, '-')) {
+        Token beginToken = node.receiver.getBeginToken();
+        if (identical(beginToken.stringValue, opString)) {
+          sb.write(' ');
+        }
+      }
+    }
     unparseSendReceiver(node, spacesNeeded: spacesNeeded);
     if (!node.isPrefix && !node.isIndex) visit(node.selector);
     if (spacesNeeded) sb.write(' ');
-    // Also add a space for sequences like x + +1 and y - -y.
-    // TODO(ahe): remove case for '+' when we drop the support for it.
-    if (node.argumentsNode != null && (identical(opString, '-')
-        || identical(opString, '+'))) {
+    // Also add a space for sequences like y - -y.
+    if (node.argumentsNode != null && identical(opString, '-')) {
       Token beginToken = node.argumentsNode.getBeginToken();
       if (beginToken != null && identical(beginToken.stringValue, opString)) {
         sb.write(' ');
       }
     }
     visit(node.argumentsNode);
   }
 
   visitSendSet(SendSet node) {
     if (node.isPrefix) {
@@ skipping 295 matching lines @@
   }
 
   visitStatement(Statement node) {
     throw 'internal error'; // Should not be called.
   }
 
   visitStringNode(StringNode node) {
     throw 'internal error'; // Should not be called.
   }
 }