Added new version of reduce.

samples/swarm/swarm_ui_lib/observable/observable.dart

 // Copyright (c) 2011, 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 observable;
 
 import 'dart:collection';
 
 part 'ChangeEvent.dart';
 part 'EventBatch.dart';
@@ skipping 173 matching lines @@
   int push(T element) {
     recordListInsert(length, element);
     _internal.add(element);
     return _internal.length;
   }
 
   T get first => _internal.first;
   T get last => _internal.last;
   T get single => _internal.single;
 
-  T min([int compare(T a, T b)]) => _internal.min(compare);
-  T max([int compare(T a, T b)]) => _internal.max(compare);
-
   void insert(int index, T element) {
     _internal.insert(index, element);
     recordListInsert(index, element);
   }
 
   T removeLast() {
     final result = _internal.removeLast();
     recordListRemove(length, result);
     return result;
   }
@@ skipping 66 matching lines @@
   }
 
   List getRange(int start, int length) {
     throw new UnimplementedError();
   }
 
   bool contains(T element) {
     throw new UnimplementedError();
   }
 
-  dynamic reduce(var initialValue,
-                 dynamic combine(var previousValue, T element)) {
+  T reduce(T combine(T previousValue, T element)) {
     throw new UnimplementedError();
   }
 
   dynamic fold(var initialValue,
                dynamic combine(var previousValue, T element)) {
     throw new UnimplementedError();
   }
 
   // Iterable<T>:
   Iterator<T> get iterator => _internal.iterator;
@@ skipping 44 matching lines @@
     // Only fire on an actual change.
     if (!identical(newValue, _value)) {
       final oldValue = _value;
       _value = newValue;
       recordPropertyUpdate("value", newValue, oldValue);
     }
   }
 
   T _value;
 }