blob: 4c31b12998e58f7b07a0a5e3b92d70c898bad1c9 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/*
* Copyright (C) 2012 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.common.collect;
import static com.google.common.base.Preconditions.checkElementIndex;
import com.google.common.annotations.GwtCompatible;
import com.google.common.math.IntMath;
import java.util.AbstractList;
import java.util.List;
import java.util.ListIterator;
import java.util.RandomAccess;
import javax.annotation.CheckForNull;
/**
* Implementation of {@link Lists#cartesianProduct(List)}.
*
* @author Louis Wasserman
*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class CartesianList<E> extends AbstractList<List<E>> implements RandomAccess {
private final transient ImmutableList<List<E>> axes;
private final transient int[] axesSizeProduct;
static <E> List<List<E>> create(List<? extends List<? extends E>> lists) {
ImmutableList.Builder<List<E>> axesBuilder = new ImmutableList.Builder<>(lists.size());
for (List<? extends E> list : lists) {
List<E> copy = ImmutableList.copyOf(list);
if (copy.isEmpty()) {
return ImmutableList.of();
}
axesBuilder.add(copy);
}
return new CartesianList<>(axesBuilder.build());
}
CartesianList(ImmutableList<List<E>> axes) {
this.axes = axes;
int[] axesSizeProduct = new int[axes.size() + 1];
axesSizeProduct[axes.size()] = 1;
try {
for (int i = axes.size() - 1; i >= 0; i--) {
axesSizeProduct[i] = IntMath.checkedMultiply(axesSizeProduct[i + 1], axes.get(i).size());
}
} catch (ArithmeticException e) {
throw new IllegalArgumentException(
"Cartesian product too large; must have size at most Integer.MAX_VALUE");
}
this.axesSizeProduct = axesSizeProduct;
}
private int getAxisIndexForProductIndex(int index, int axis) {
return (index / axesSizeProduct[axis + 1]) % axes.get(axis).size();
}
@Override
public int indexOf(@CheckForNull Object o) {
if (!(o instanceof List)) {
return -1;
}
List<?> list = (List<?>) o;
if (list.size() != axes.size()) {
return -1;
}
ListIterator<?> itr = list.listIterator();
int computedIndex = 0;
while (itr.hasNext()) {
int axisIndex = itr.nextIndex();
int elemIndex = axes.get(axisIndex).indexOf(itr.next());
if (elemIndex == -1) {
return -1;
}
computedIndex += elemIndex * axesSizeProduct[axisIndex + 1];
}
return computedIndex;
}
@Override
public int lastIndexOf(@CheckForNull Object o) {
if (!(o instanceof List)) {
return -1;
}
List<?> list = (List<?>) o;
if (list.size() != axes.size()) {
return -1;
}
ListIterator<?> itr = list.listIterator();
int computedIndex = 0;
while (itr.hasNext()) {
int axisIndex = itr.nextIndex();
int elemIndex = axes.get(axisIndex).lastIndexOf(itr.next());
if (elemIndex == -1) {
return -1;
}
computedIndex += elemIndex * axesSizeProduct[axisIndex + 1];
}
return computedIndex;
}
@Override
public ImmutableList<E> get(int index) {
checkElementIndex(index, size());
return new ImmutableList<E>() {
@Override
public int size() {
return axes.size();
}
@Override
public E get(int axis) {
checkElementIndex(axis, size());
int axisIndex = getAxisIndexForProductIndex(index, axis);
return axes.get(axis).get(axisIndex);
}
@Override
boolean isPartialView() {
return true;
}
};
}
@Override
public int size() {
return axesSizeProduct[0];
}
@Override
public boolean contains(@CheckForNull Object object) {
if (!(object instanceof List)) {
return false;
}
List<?> list = (List<?>) object;
if (list.size() != axes.size()) {
return false;
}
int i = 0;
for (Object o : list) {
if (!axes.get(i).contains(o)) {
return false;
}
i++;
}
return true;
}
}
|