Fixes in smoke, which in turn should fix todomvc.

pkg/observe/lib/src/path_observer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library observe.src.path_observer;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:math' show min;
 @MirrorsUsed(metaTargets: const [Reflectable, ObservableProperty],
@@ skipping 488 matching lines @@
   bool get _isOpen => _notifyCallback != null;
 
   /// The number of arguments the subclass will pass to [_report].
   int get _reportArgumentCount;
 
   open(callback) {
     if (_isOpen || _isClosed) {
       throw new StateError('Observer has already been opened.');
     }
 
-    if (_minArgumentCount(callback) > _reportArgumentCount) {
+    if (smoke.minArgs(callback) > _reportArgumentCount) {
       throw new ArgumentError('callback should take $_reportArgumentCount or '
           'fewer arguments');
     }
 
     _notifyCallback = callback;
-    _notifyArgumentCount = min(_reportArgumentCount,
-        _maxArgumentCount(callback));
+    _notifyArgumentCount = min(_reportArgumentCount, smoke.maxArgs(callback));
 
     _connect();
     return _value;
   }
 
   get value {
     _check(skipChanges: true);
     return _value;
   }
 
@@ skipping 26 matching lines @@
         case 3: _notifyCallback(newValue, oldValue, extraArg); break;
       }
     } catch (e, s) {
       // Deliver errors async, so if a single callback fails it doesn't prevent
       // other things from working.
       new Completer().completeError(e, s);
     }
   }
 }
 
-typedef _Func0();
-typedef _Func1(a);
-typedef _Func2(a, b);
-typedef _Func3(a, b, c);
-
-int _minArgumentCount(fn) {

[Siggi Cherem (dart-lang), 2014/02/25 23:23:23]

I forgot to delete this last time (now that smoke has it there too)

-  if (fn is _Func0) return 0;
-  if (fn is _Func1) return 1;
-  if (fn is _Func2) return 2;
-  if (fn is _Func3) return 3;
-  return 4; // at least 4 arguments are required.
-}
-
-int _maxArgumentCount(fn) {
-  if (fn is _Func3) return 3;
-  if (fn is _Func2) return 2;
-  if (fn is _Func1) return 1;
-  if (fn is _Func0) return 0;
-  return -1;
-}
-
 class _ObservedSet {
   /// To prevent sequential [PathObserver]s and [CompoundObserver]s from
   /// observing the same object, we check if they are observing the same root
   /// as the most recently created observer, and if so merge it into the
   /// existing _ObservedSet.
   ///
   /// See <https://github.com/Polymer/observe-js/commit/f0990b1> and
   /// <https://codereview.appspot.com/46780044/>.
   static _ObservedSet _lastSet;
 
@@ skipping 84 matching lines @@
     for (var observer in _observers.values.toList(growable: false)) {
       if (observer._isOpen) observer._check();
     }
 
     _resetNeeded = true;
     scheduleMicrotask(reset);
   }
 }
 
 const int _MAX_DIRTY_CHECK_CYCLES = 1000;