io.jenetics.lattices.Self Maven / Gradle / Ivy

Go to download
/*
 * Java Lattice Library (lattices-3.0.0.ALPHA1).
 * Copyright (c) 2022-2022 Franz Wilhelmstötter
 *
 * 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.
 *
 * Author:
 *    Franz Wilhelmstötter ([email protected])
 */
package io.jenetics.lattices;

/**
 * This interface defines a recursive generic type {@code S}, which
 * represents the type of the implementing class.
 * {@code
 * interface Foo> extends Self {
 *     // ...
 * }
 * }
 * Using the {@code Self} interface in this case makes it clear that the generic
 * type {@code T} of the interface {@code Foo} represents the concrete type of
 * the class, implementing the interface {@code Foo}.
 * 
 * If the interface is used as intended, the following generic {@code min} method
 * can be implemented as a default method.
 * 
{@code
 * interface Foo> extends Self, Comparable {
 *     // ...
 *
 *     default A max(final A other) {
 *         return compareTo(other) > 0 ? self() : other;
 *     }
 * }
 * }

 *
 * @param  the type of the implementing class.
 *
 * @author Franz Wilhelmstötter
 * @since 3.0
 * @version 3.0
 */
public interface Self> {

    /**
     * Return a reference of {@code this} object as the declared generic type
     * {@code S}.
     *
     * @return the {@code this} reference as the generic type {@code S}
     * @throws ClassCastException if the interface is not used as intended and
     *         {@code (this instanceof S) == false}
     */
    @SuppressWarnings("unchecked")
    default S self() {
        return (S)this;
    }

}