/*
* Copyright 2000-2015 JetBrains s.r.o.
*
* 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.intellij.diff.util;
import com.intellij.util.Function;
import com.intellij.util.containers.ContainerUtil;
import org.jetbrains.annotations.Contract;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.List;
public enum ThreeSide {
LEFT(0),
BASE(1),
RIGHT(2);
private final int myIndex;
ThreeSide(int index) {
myIndex = index;
}
@NotNull
public static ThreeSide fromIndex(int index) {
if (index == 0) return LEFT;
if (index == 1) return BASE;
if (index == 2) return RIGHT;
throw new IndexOutOfBoundsException("index: " + index);
}
public int getIndex() {
return myIndex;
}
//
// Helpers
//
@Nullable
@Contract("!null, !null, !null -> !null; null, null, null -> null")
public <T> T select(@Nullable T left, @Nullable T base, @Nullable T right) {
if (myIndex == 0) return left;
if (myIndex == 1) return base;
if (myIndex == 2) return right;
//noinspection Contract
throw new IllegalStateException();
}
@NotNull
public <T> T selectNotNull(@NotNull T left, @NotNull T base, @NotNull T right) {
if (myIndex == 0) return left;
if (myIndex == 1) return base;
if (myIndex == 2) return right;
throw new IllegalStateException();
}
public int select(@NotNull int[] array) {
assert array.length == 3;
return array[myIndex];
}
public <T> T select(@NotNull T[] array) {
assert array.length == 3;
return array[myIndex];
}
@NotNull
public <T> T selectNotNull(@NotNull T[] array) {
assert array.length == 3;
return array[myIndex];
}
public <T> T select(@NotNull List<T> list) {
assert list.size() == 3;
return list.get(myIndex);
}
@NotNull
public <T> T selectNotNull(@NotNull List<T> list) {
assert list.size() == 3;
return list.get(myIndex);
}
@Nullable
public static <T> ThreeSide fromValue(@NotNull List<? extends T> list, @Nullable T value) {
assert list.size() == 3;
int index = list.indexOf(value);
return index != -1 ? fromIndex(index) : null;
}
@NotNull
public static <T> List<T> map(@NotNull Function<ThreeSide, T> function) {
return ContainerUtil.list(
function.fun(LEFT),
function.fun(BASE),
function.fun(RIGHT)
);
}
}