[mdv] implement Node.createBinding and Node.createBindings

pkg/mdv/lib/src/template_iterator.dart

Index: pkg/mdv/lib/src/template_iterator.dart
diff --git a/pkg/mdv/lib/src/template_iterator.dart b/pkg/mdv/lib/src/template_iterator.dart
index 1c76e617713540ab187508d00c79a60058a876b7..8cca7ce8d50b5346f8c3bd1a63a20da0edb68b22 100644
--- a/pkg/mdv/lib/src/template_iterator.dart
+++ b/pkg/mdv/lib/src/template_iterator.dart
@@ -239,7 +239,7 @@ class _TemplateIterator {
     iteratedValue = value;
 
     if (iteratedValue is Observable) {
-      _sub = iteratedValue.changes.listen(_handleChanges);
+      _sub = (iteratedValue as Observable).changes.listen(_handleChanges);

[Siggi Cherem (dart-lang), 2013/07/25 16:24:12]

How crazy would it be to add as a language feature that we use 'is' checks to
infer the type sensitively in a block of code? I know the editor already uses it
for 'var', but I wonder if it can be used more generally:

T x;
x.foo; // warning: foo not in T
if (x is V) {
  x.foo; // ok: foo is defined in V
}

     }
 
     var splices = calculateSplices(