1   /*
2    * Copyright (C) 2008 The Guava Authors
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    * http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package com.google.common.collect.testing;
18  
19  import com.google.common.annotations.GwtCompatible;
20  
21  import java.util.Collections;
22  import java.util.EnumSet;
23  import java.util.Iterator;
24  import java.util.ListIterator;
25  import java.util.Set;
26  
27  /**
28   * A method supported by implementations of the {@link Iterator} or
29   * {@link ListIterator} interface.
30   *
31   * <p>This enum is GWT compatible.
32   *
33   * @author Chris Povirk
34   */
35  @GwtCompatible
36  public enum IteratorFeature {
37    /**
38     * Support for {@link Iterator#remove()}.
39     */
40    SUPPORTS_REMOVE,
41    /**
42     * Support for {@link ListIterator#add(Object)}; ignored for plain
43     * {@link Iterator} implementations.
44     */
45    SUPPORTS_ADD,
46    /**
47     * Support for {@link ListIterator#set(Object)}; ignored for plain
48     * {@link Iterator} implementations.
49     */
50    SUPPORTS_SET;
51  
52    /**
53     * A set containing none of the optional features of the {@link Iterator} or
54     * {@link ListIterator} interfaces.
55     */
56    public static final Set<IteratorFeature> UNMODIFIABLE =
57        Collections.emptySet();
58  
59    /**
60     * A set containing all of the optional features of the {@link Iterator} and
61     * {@link ListIterator} interfaces.
62     */
63    public static final Set<IteratorFeature> MODIFIABLE =
64        Collections.unmodifiableSet(EnumSet.allOf(IteratorFeature.class));
65  }