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A packaging of the IntelliJ Community Edition util library.
This is release number 1 of trunk branch 142.
The newest version!
/*
* Copyright 2000-2013 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.util.containers;
import com.intellij.openapi.util.Key;
import org.jetbrains.annotations.NotNull;
/**
* @author peter
*/
public abstract class ImmutableUserMap {
public static final ImmutableUserMap EMPTY = new ImmutableUserMap() {
@Override
public T get(@NotNull final Key key) {
return null;
}
};
private ImmutableUserMap() {
}
public abstract T get(@NotNull Key key);
public final ImmutableUserMap put(@NotNull final Key key, final T value) {
return new ImmutableUserMapImpl(key, value, this);
}
private static class ImmutableUserMapImpl extends ImmutableUserMap {
private final Key myKey;
private final V myValue;
private final ImmutableUserMap myNext;
private ImmutableUserMapImpl(final Key key, final V value, final ImmutableUserMap next) {
myKey = key;
myNext = next;
myValue = value;
}
@Override
public T get(@NotNull final Key key) {
if (key.equals(myKey)) return (T)myValue;
return myNext.get(key);
}
}
}