/*
* Copyright (C) 2011 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 com.google.common.annotations.GwtCompatible;
import javax.annotation.Nullable;
/**
* A factory for copying nodes in binary search trees with different children.
*
* <p>Typically, nodes will carry more information than the fields in the {@link BstNode} class,
* often some kind of value or some aggregate data for the subtree. This factory is responsible for
* copying this additional data between nodes.
*
* @author Louis Wasserman
* @param <N> The type of the tree nodes constructed with this {@code BstNodeFactory}.
*/
@GwtCompatible
abstract class BstNodeFactory<N extends BstNode<?, N>> {
/**
* Returns a new {@code N} with the key and value data from {@code source}, with left child
* {@code left}, and right child {@code right}. If {@code left} or {@code right} is null, the
* returned node will not have a child on the corresponding side.
*/
public abstract N createNode(N source, @Nullable N left, @Nullable N right);
/**
* Returns a new {@code N} with the key and value data from {@code source} that is a leaf.
*/
public final N createLeaf(N source) {
return createNode(source, null, null);
}
}
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