001 /*
002 * Java Genetic Algorithm Library (jenetics-3.7.0).
003 * Copyright (c) 2007-2016 Franz Wilhelmstötter
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 *
017 * Author:
018 * Franz Wilhelmstötter (franz.wilhelmstoetter@gmx.at)
019 */
020 package org.jenetics.engine;
021
022 import static java.util.Objects.requireNonNull;
023
024 import java.util.function.Function;
025
026 import org.jenetics.Gene;
027
028 /**
029 * This interface describes a <i>problem</i> which can be solved by the GA
030 * evolution {@code Engine}. It connects the actual {@link #fitness()} function
031 * and the needed {@link #codec()}.
032 *
033 * @see Codec
034 * @see Engine
035 *
036 * @param <T> the (<i>native</i>) argument type of the problem fitness function
037 * @param <G> the gene type the evolution engine is working with
038 * @param <C> the result type of the fitness function
039 *
040 * @author <a href="mailto:franz.wilhelmstoetter@gmx.at">Franz Wilhelmstötter</a>
041 * @version 3.4
042 * @since 3.4
043 */
044 public interface Problem<
045 T,
046 G extends Gene<?, G>,
047 C extends Comparable<? super C>
048 >
049 {
050
051 /**
052 * Return the fitness function of the <i>problem</i> in the <i>native</i>
053 * problem domain.
054 *
055 * @return the fitness function
056 */
057 public Function<T, C> fitness();
058
059 /**
060 * Return the codec, which translates the types of the problem domain into
061 * types, which can be understand by the evolution {@code Engine}.
062 *
063 * @return the engine codec
064 */
065 public Codec<T, G> codec();
066
067 /**
068 * Return a new optimization <i>problem</i> with the given parameters.
069 *
070 * @param fitness the problem fitness function
071 * @param codec the evolution engine codec
072 * @param <T> the (<i>native</i>) argument type of the problem fitness function
073 * @param <G> the gene type the evolution engine is working with
074 * @param <C> the result type of the fitness function
075 * @return a new problem object from the given parameters
076 * @throws NullPointerException if one of the arguments is {@code null}
077 */
078 public static <T, G extends Gene<?, G>, C extends Comparable<? super C>>
079 Problem<T, G, C> of(
080 final Function<T, C> fitness,
081 final Codec<T, G> codec
082 ) {
083 requireNonNull(fitness);
084 requireNonNull(codec);
085
086 return new Problem<T, G, C>() {
087 @Override
088 public Codec<T, G> codec() {
089 return codec;
090 }
091
092 @Override
093 public Function<T, C> fitness() {
094 return fitness;
095 }
096 };
097 }
098
099 }
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