1/*
2 * Copyright (C) 2009 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the
10 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
11 * express or implied. See the License for the specific language governing permissions and
12 * limitations under the License.
13 */
14
15package com.google.common.collect;
16
17import com.google.common.annotations.GwtCompatible;
18import com.google.common.annotations.GwtIncompatible;
19
20import java.util.Comparator;
21
22import javax.annotation.Nullable;
23
24/**
25 * List returned by {@code ImmutableSortedSet.asList()} when the set isn't empty.
26 *
27 * @author Jared Levy
28 * @author Louis Wasserman
29 */
30@GwtCompatible(emulated = true)
31@SuppressWarnings("serial")
32final class ImmutableSortedAsList<E> extends RegularImmutableAsList<E>
33    implements SortedIterable<E> {
34  ImmutableSortedAsList(
35      ImmutableSortedSet<E> backingSet, ImmutableList<E> backingList) {
36    super(backingSet, backingList);
37  }
38
39  @Override
40  ImmutableSortedSet<E> delegateCollection() {
41    return (ImmutableSortedSet<E>) super.delegateCollection();
42  }
43
44  @Override public Comparator<? super E> comparator() {
45    return delegateCollection().comparator();
46  }
47
48  // Override indexOf() and lastIndexOf() to be O(log N) instead of O(N).
49
50  @GwtIncompatible("ImmutableSortedSet.indexOf")
51  // TODO(cpovirk): consider manual binary search under GWT to preserve O(log N) lookup
52  @Override public int indexOf(@Nullable Object target) {
53    int index = delegateCollection().indexOf(target);
54
55    // TODO(kevinb): reconsider if it's really worth making feeble attempts at
56    // sanity for inconsistent comparators.
57
58    // The equals() check is needed when the comparator isn't compatible with
59    // equals().
60    return (index >= 0 && get(index).equals(target)) ? index : -1;
61  }
62
63  @GwtIncompatible("ImmutableSortedSet.indexOf")
64  @Override public int lastIndexOf(@Nullable Object target) {
65    return indexOf(target);
66  }
67
68  @Override
69  public boolean contains(Object target) {
70    // Necessary for ISS's with comparators inconsistent with equals.
71    return indexOf(target) >= 0;
72  }
73
74  @GwtIncompatible("super.subListUnchecked does not exist; inherited subList is valid if slow")
75  /*
76   * TODO(cpovirk): if we start to override indexOf/lastIndexOf under GWT, we'll want some way to
77   * override subList to return an ImmutableSortedAsList for better performance. Right now, I'm not
78   * sure there's any performance hit from our failure to override subListUnchecked under GWT
79   */
80  @Override
81  ImmutableList<E> subListUnchecked(int fromIndex, int toIndex) {
82    return new RegularImmutableSortedSet<E>(
83        super.subListUnchecked(fromIndex, toIndex), comparator())
84        .asList();
85  }
86}
87