Initial commit of Effen reactive framework experiment for Sky

sky/examples/fn/lib/fn.dart

+library fn;
+
+import 'dart:async';
+import 'dart:collection';
+import 'dart:sky' as sky;
+import 'reflect.dart' as reflect;
+
+part 'component.dart';
+part 'node.dart';
+part 'style.dart';
+
+bool _checkedMode;
+
+bool debugWarnings() {
+  void testFn(double i) {}
+
+  if (_checkedMode == null) {
+    _checkedMode = false;
+    try {
+      testFn('not a double');
+    } catch (ex) {
+      _checkedMode = true;
+    }
+  }
+
+  return _checkedMode;
+}