Implementation of null-aware operators.

pkg/compiler/lib/src/resolution/send_resolver.dart

Index: pkg/compiler/lib/src/resolution/send_resolver.dart
diff --git a/pkg/compiler/lib/src/resolution/send_resolver.dart b/pkg/compiler/lib/src/resolution/send_resolver.dart
index 77e35827ceb1f87252eb1e1ca789da3b51221940..0346cdc73161142326787b3c585b15b044f5df43 100644
--- a/pkg/compiler/lib/src/resolution/send_resolver.dart
+++ b/pkg/compiler/lib/src/resolution/send_resolver.dart
@@ -224,6 +224,8 @@ abstract class SendResolverMixin {
         return const LogicalAndStructure();
       } else if (operatorText == '||') {
         return const LogicalOrStructure();
+      } else if (operatorText == '??') {
+        return const IfNullStructure();
       }
     }
 
@@ -510,7 +512,10 @@ abstract class SendResolverMixin {
       } else {
         return new StaticAccess.superMethod(element);
       }
-    } else if (node.isOperator) {
+    } else if (node.isOperator || node.isConditional) {
+      // Conditional sends (e?.x) are treated as dynamic property reads because
+      // they are equivalent to do ((a) => a == null ? null : a.x)(e). If `e` is
+      // a type `A`, this is equivalent to write `(A).x`.
       return new DynamicAccess.dynamicProperty(node.receiver);

[Johnni Winther, 2015/05/22 12:39:49]

Add a TODO for me to maybe add a DynamicAccess.conditionalDynamicProperty

[Siggi Cherem (dart-lang), 2015/05/22 19:49:54]

Done.

     } else if (Elements.isClosureSend(node, element)) {
       if (element == null) {