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

lib/compiler/implementation/tree/unparser.dart

Index: lib/compiler/implementation/tree/unparser.dart
diff --git a/lib/compiler/implementation/tree/unparser.dart b/lib/compiler/implementation/tree/unparser.dart
index a1d0fad161293cc63ed5aa3fc20af1c23fbcb288..3e868de6db70d8b8a7d1bfe4dc27c7880c6c3cdc 100644
--- a/lib/compiler/implementation/tree/unparser.dart
+++ b/lib/compiler/implementation/tree/unparser.dart
@@ -279,13 +279,18 @@ class Unparser implements Visitor {
 
   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);
   }