001 /*
002 * Java Genetic Algorithm Library (jenetics-4.4.0).
003 * Copyright (c) 2007-2019 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@gmail.com)
019 */
020 package io.jenetics;
021
022 import static java.lang.String.format;
023 import static io.jenetics.internal.util.Hashes.hash;
024
025 import java.io.Serializable;
026 import java.util.Objects;
027
028 import io.jenetics.util.ISeq;
029 import io.jenetics.util.RandomRegistry;
030
031 /**
032 * <p>
033 * Gene which holds enumerable (countable) genes. Will be used for combinatorial
034 * problems in combination with the {@link PermutationChromosome}.
035 * </p>
036 * The following code shows how to create a combinatorial genotype factory which
037 * can be used when creating an {@link io.jenetics.engine.Engine} instance.
038 * <pre>{@code
039 * final ISeq<Integer> alleles = ISeq.of(1, 2, 3, 4, 5, 6, 7, 8);
040 * final Factory<Genotype<EnumGene<Integer>>> gtf = Genotype.of(
041 * PermutationChromosome.of(alleles)
042 * );
043 * }</pre>
044 *
045 * The following code shows the assurances of the {@code EnumGene}.
046 * <pre>{@code
047 * final ISeq<Integer> alleles = ISeq.of(1, 2, 3, 4, 5, 6, 7, 8);
048 * final EnumGene<Integer> gene = new EnumGene<>(5, alleles);
049 *
050 * assert(gene.getAlleleIndex() == 5);
051 * assert(gene.getAllele() == gene.getValidAlleles().get(5));
052 * assert(gene.getValidAlleles() == alleles);
053 * }</pre>
054 *
055 * @see PermutationChromosome
056 * @see PartiallyMatchedCrossover
057 *
058 * @implNote
059 * This class is immutable and thread-safe.
060 *
061 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
062 * @since 1.0
063 * @version 4.0
064 */
065 public final class EnumGene<A>
066 implements
067 Gene<A, EnumGene<A>>,
068 Comparable<EnumGene<A>>,
069 Serializable
070 {
071
072 private static final long serialVersionUID = 2L;
073
074 private final ISeq<A> _validAlleles;
075 private final int _alleleIndex;
076
077 /**
078 * Create a new enum gene from the given valid genes and the chosen allele
079 * index.
080 *
081 * @param alleleIndex the index of the allele for this gene.
082 * @param validAlleles the sequence of valid alleles.
083 * @throws IllegalArgumentException if the give valid alleles sequence is
084 * empty
085 * @throws NullPointerException if the valid alleles seq is {@code null}.
086 */
087 EnumGene(final int alleleIndex, final ISeq<? extends A> validAlleles) {
088 if (validAlleles.isEmpty()) {
089 throw new IllegalArgumentException(
090 "Array of valid alleles must be greater than zero."
091 );
092 }
093
094 if (alleleIndex < 0 || alleleIndex >= validAlleles.length()) {
095 throw new IndexOutOfBoundsException(format(
096 "Allele index is not in range [0, %d).", alleleIndex
097 ));
098 }
099
100 _validAlleles = ISeq.upcast(validAlleles);
101 _alleleIndex = alleleIndex;
102 }
103
104 /**
105 * Return sequence of the valid alleles where this gene is a part of.
106 *
107 * @return the sequence of the valid alleles.
108 */
109 public ISeq<A> getValidAlleles() {
110 return _validAlleles;
111 }
112
113 /**
114 * Return the index of the allele this gene is representing.
115 *
116 * @return the index of the allele this gene is representing.
117 */
118 public int getAlleleIndex() {
119 return _alleleIndex;
120 }
121
122 @Override
123 public A getAllele() {
124 return _validAlleles.get(_alleleIndex);
125 }
126
127 @Override
128 public boolean isValid() {
129 return _alleleIndex >= 0 && _alleleIndex < _validAlleles.length();
130 }
131
132 @Override
133 public EnumGene<A> newInstance() {
134 return new EnumGene<>(
135 RandomRegistry.getRandom().nextInt(_validAlleles.length()),
136 _validAlleles
137 );
138 }
139
140 /**
141 * Create a new gene from the given {@code value} and the gene context.
142 *
143 * @since 1.6
144 *
145 * @param value the value of the new gene.
146 * @return a new gene with the given value.
147 */
148 public EnumGene<A> newInstance(final A value) {
149 return new EnumGene<>(
150 _validAlleles.indexOf(value),
151 _validAlleles
152 );
153 }
154
155 @Override
156 public int compareTo(final EnumGene<A> gene) {
157 int result = 0;
158 if (_alleleIndex > gene._alleleIndex) {
159 result = 1;
160 } else if (_alleleIndex < gene._alleleIndex) {
161 result = -1;
162 }
163
164 return result;
165 }
166
167 @Override
168 public int hashCode() {
169 return hash(_alleleIndex, hash(_validAlleles));
170 }
171
172 @Override
173 public boolean equals(final Object obj) {
174 return obj == this ||
175 obj instanceof EnumGene &&
176 Objects.equals(((EnumGene)obj)._alleleIndex, _alleleIndex) &&
177 Objects.equals(((EnumGene)obj)._validAlleles, _validAlleles);
178 }
179
180 @Override
181 public String toString() {
182 return Objects.toString(getAllele());
183 }
184
185
186 /* *************************************************************************
187 * Static object creation methods
188 * ************************************************************************/
189
190 /**
191 * Create a new enum gene from the given valid genes and the chosen allele
192 * index.
193 *
194 * @since 3.4
195 *
196 * @param <A> the allele type
197 * @param alleleIndex the index of the allele for this gene.
198 * @param validAlleles the sequence of valid alleles.
199 * @return a new {@code EnumGene} with the given with the allele
200 * {@code validAlleles.get(alleleIndex)}
201 * @throws IllegalArgumentException if the give valid alleles sequence is
202 * empty
203 * @throws NullPointerException if the valid alleles seq is {@code null}.
204 */
205 public static <A> EnumGene<A> of(
206 final int alleleIndex,
207 final ISeq<? extends A> validAlleles
208 ) {
209 return new EnumGene<>(alleleIndex, validAlleles);
210 }
211
212 /**
213 * Return a new enum gene with an allele randomly chosen from the given
214 * valid alleles.
215 *
216 * @param <A> the allele type
217 * @param validAlleles the sequence of valid alleles.
218 * @return a new {@code EnumGene} with an randomly chosen allele from the
219 * sequence of valid alleles
220 * @throws java.lang.IllegalArgumentException if the give valid alleles
221 * sequence is empty
222 * @throws NullPointerException if the valid alleles seq is {@code null}.
223 */
224 public static <A> EnumGene<A> of(final ISeq<? extends A> validAlleles) {
225 return new EnumGene<>(
226 RandomRegistry.getRandom().nextInt(validAlleles.length()),
227 validAlleles
228 );
229 }
230
231 /**
232 * Create a new enum gene from the given valid genes and the chosen allele
233 * index.
234 *
235 * @param <A> the allele type
236 * @param alleleIndex the index of the allele for this gene.
237 * @param validAlleles the array of valid alleles.
238 * @return a new {@code EnumGene} with the given with the allele
239 * {@code validAlleles[alleleIndex]}
240 * @throws java.lang.IllegalArgumentException if the give valid alleles
241 * array is empty of the allele index is out of range.
242 */
243 @SafeVarargs
244 public static <A> EnumGene<A> of(
245 final int alleleIndex,
246 final A... validAlleles
247 ) {
248 return new EnumGene<>(alleleIndex, ISeq.of(validAlleles));
249 }
250
251 /**
252 * Return a new enum gene with an allele randomly chosen from the given
253 * valid alleles.
254 *
255 * @param <A> the allele type
256 * @param validAlleles the array of valid alleles.
257 * @return a new {@code EnumGene} with an randomly chosen allele from the
258 * sequence of valid alleles
259 * @throws IllegalArgumentException if the give valid alleles array is empty
260 */
261 @SafeVarargs
262 public static <A> EnumGene<A> of(final A... validAlleles) {
263 return EnumGene.of(ISeq.of(validAlleles));
264 }
265
266 }
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