Initial commit of Effen reactive framework experiment for Sky

sky/examples/fn/lib/reflect.dart

Index: sky/examples/fn/lib/reflect.dart
diff --git a/sky/examples/fn/lib/reflect.dart b/sky/examples/fn/lib/reflect.dart
new file mode 100644
index 0000000000000000000000000000000000000000..66b2efefc2ea698c86a7c7cd98819750f054157c
--- /dev/null
+++ b/sky/examples/fn/lib/reflect.dart
@@ -0,0 +1,41 @@
+library reflect;
+
+import 'dart:mirrors';
+import 'dart:collection';
+
+HashMap<ClassMirror, List> _fieldCache = new HashMap<ClassMirror, List>();
+
+List<Symbol> _getPublicFields(ClassMirror mirror) {
+  var fields = _fieldCache[mirror];
+  if (fields == null) {
+    fields = new List<Symbol>();
+    _fieldCache[mirror] = fields;
+
+    while (mirror != null) {
+      var decls = mirror.declarations;
+      fields.addAll(decls.keys.where((symbol) {
+        var mirror = decls[symbol];
+        if (mirror is! VariableMirror) {
+          return false;
+        }
+
+        var vMirror = mirror as VariableMirror;
+        return !vMirror.isPrivate && !vMirror.isStatic && !vMirror.isFinal;
+      }));
+
+      mirror = mirror.superclass;
+    }
+  }
+
+  return fields;
+}
+
+void copyPublicFields(Object source, Object target) {
+  assert(source.runtimeType == target.runtimeType);
+
+  var sourceMirror = reflect(source);
+  var targetMirror = reflect(target);
+  for (var symbol in _getPublicFields(sourceMirror.type)) {
+    targetMirror.setField(symbol, sourceMirror.getField(symbol).reflectee);
+  }
+}