/* Copyright (C) 2013-2020 TU Dortmund
 * This file is part of LearnLib, http://www.learnlib.de/.
 *
 * 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 de.learnlib.datastructure.list;

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Interface for objects that may occur in a {@link IntrusiveList}, either as a value element or the head of the list
 * (which represents the list itself, but does not carry any value).
 * <p>
 * The purpose of this class is to enable managing block lists <i>intrusively</i>.
 *
 * @param <T>
 *         input symbol type
 *
 * @author Malte Isberner
 */
public interface IntrusiveListElem<T> {

    @Nullable T getNextElement();

    void setNextElement(@Nullable T nextBlock);

}
