Added getField/setField to ObjectMirror. For InstanceMirrors, this get/sets

runtime/lib/mirrors_impl.dart

Index: runtime/lib/mirrors_impl.dart
===================================================================
--- runtime/lib/mirrors_impl.dart	(revision 9728)
+++ runtime/lib/mirrors_impl.dart	(working copy)
@@ -125,8 +125,48 @@
     return completer.future;
   }
 
+  Future<InstanceMirror> getField(String fieldName)
+  {
+    Completer<InstanceMirror> completer = new Completer<InstanceMirror>();
+    try {
+      completer.complete(

[turnidge, 2012/07/17 23:59:33]

Can this fit on one line?

+          _getField(this, fieldName));
+    } catch (var exception) {
+      completer.completeException(exception);
+    }
+    return completer.future;
+  }
+
+  Future<InstanceMirror> setField(String fieldName, Object arg)
+  {
+    if (arg is Mirror) {
+      if (arg is! InstanceMirror) {
+        throw new MirrorException(
+            'argument ($arg) was not an InstanceMirror');
+      }
+    } else if (!isSimpleValue(arg)) {
+      throw new MirrorException(
+          'argument ($arg) was not a simple value');

[turnidge, 2012/07/17 23:59:33]

Maybe make a helper function for arg checking to avoid duplicating this code.

+    }
+
+    Completer<InstanceMirror> completer = new Completer<InstanceMirror>();
+    try {
+      completer.complete(

[turnidge, 2012/07/17 23:59:33]

Can this fit on one line?

+          _setField(this, fieldName, arg));
+    } catch (var exception) {
+      completer.completeException(exception);
+    }
+    return completer.future;
+  }
+
   static _invoke(ref, memberName, positionalArguments)
       native 'LocalObjectMirrorImpl_invoke';
+
+  static _getField(ref, fieldName)
+      native 'LocalObjectMirrorImpl_getField';
+
+  static _setField(ref, fieldName, value)
+      native 'LocalObjectMirrorImpl_setField';
 }
 
 // Prints a string as it might appear in dart program text.