001 /*
002 * Java Genetic Algorithm Library (jenetics-6.1.0).
003 * Copyright (c) 2007-2020 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.alleleIndex() == 5);
051 * assert(gene.allele() == gene.validAlleles().get(5));
052 * assert(gene.validAlleles() == 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 5.2
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): %d.",
097 validAlleles.length(),
098 alleleIndex
099 ));
100 }
101
102 _validAlleles = ISeq.upcast(validAlleles);
103 _alleleIndex = alleleIndex;
104 }
105
106 /**
107 * Return sequence of the valid alleles where this gene is a part of.
108 *
109 * @return the sequence of the valid alleles.
110 */
111 public ISeq<A> validAlleles() {
112 return _validAlleles;
113 }
114
115 /**
116 * Return the index of the allele this gene is representing.
117 *
118 * @return the index of the allele this gene is representing.
119 */
120 public int alleleIndex() {
121 return _alleleIndex;
122 }
123
124 @Override
125 public A allele() {
126 return _validAlleles.get(_alleleIndex);
127 }
128
129 @Override
130 public boolean isValid() {
131 return _alleleIndex >= 0 && _alleleIndex < _validAlleles.length();
132 }
133
134 @Override
135 public EnumGene<A> newInstance() {
136 return new EnumGene<>(
137 RandomRegistry.random().nextInt(_validAlleles.length()),
138 _validAlleles
139 );
140 }
141
142 /**
143 * Create a new gene from the given {@code value} and the gene context.
144 *
145 * @since 1.6
146 *
147 * @param value the value of the new gene.
148 * @return a new gene with the given value.
149 */
150 public EnumGene<A> newInstance(final A value) {
151 return new EnumGene<>(
152 _validAlleles.indexOf(value),
153 _validAlleles
154 );
155 }
156
157 @Override
158 public int compareTo(final EnumGene<A> gene) {
159 int result = 0;
160 if (_alleleIndex > gene._alleleIndex) {
161 result = 1;
162 } else if (_alleleIndex < gene._alleleIndex) {
163 result = -1;
164 }
165
166 return result;
167 }
168
169 @Override
170 public int hashCode() {
171 return hash(_alleleIndex, hash(_validAlleles));
172 }
173
174 @Override
175 public boolean equals(final Object obj) {
176 return obj == this ||
177 obj instanceof EnumGene &&
178 Objects.equals(((EnumGene)obj)._alleleIndex, _alleleIndex) &&
179 Objects.equals(((EnumGene)obj)._validAlleles, _validAlleles);
180 }
181
182 @Override
183 public String toString() {
184 return Objects.toString(allele());
185 }
186
187
188 /* *************************************************************************
189 * Static object creation methods
190 * ************************************************************************/
191
192 /**
193 * Create a new enum gene from the given valid genes and the chosen allele
194 * index.
195 *
196 * @since 3.4
197 *
198 * @param <A> the allele type
199 * @param alleleIndex the index of the allele for this gene.
200 * @param validAlleles the sequence of valid alleles.
201 * @return a new {@code EnumGene} with the given with the allele
202 * {@code validAlleles.get(alleleIndex)}
203 * @throws IllegalArgumentException if the give valid alleles sequence is
204 * empty
205 * @throws NullPointerException if the valid alleles seq is {@code null}.
206 */
207 public static <A> EnumGene<A> of(
208 final int alleleIndex,
209 final ISeq<? extends A> validAlleles
210 ) {
211 return new EnumGene<>(alleleIndex, validAlleles);
212 }
213
214 /**
215 * Return a new enum gene with an allele randomly chosen from the given
216 * valid alleles.
217 *
218 * @param <A> the allele type
219 * @param validAlleles the sequence of valid alleles.
220 * @return a new {@code EnumGene} with an randomly chosen allele from the
221 * sequence of valid alleles
222 * @throws java.lang.IllegalArgumentException if the give valid alleles
223 * sequence is empty
224 * @throws NullPointerException if the valid alleles seq is {@code null}.
225 */
226 public static <A> EnumGene<A> of(final ISeq<? extends A> validAlleles) {
227 return new EnumGene<>(
228 RandomRegistry.random().nextInt(validAlleles.length()),
229 validAlleles
230 );
231 }
232
233 /**
234 * Create a new enum gene from the given valid genes and the chosen allele
235 * index.
236 *
237 * @param <A> the allele type
238 * @param alleleIndex the index of the allele for this gene.
239 * @param validAlleles the array of valid alleles.
240 * @return a new {@code EnumGene} with the given with the allele
241 * {@code validAlleles[alleleIndex]}
242 * @throws java.lang.IllegalArgumentException if the give valid alleles
243 * array is empty of the allele index is out of range.
244 */
245 @SafeVarargs
246 public static <A> EnumGene<A> of(
247 final int alleleIndex,
248 final A... validAlleles
249 ) {
250 return new EnumGene<>(alleleIndex, ISeq.of(validAlleles));
251 }
252
253 /**
254 * Return a new enum gene with an allele randomly chosen from the given
255 * valid alleles.
256 *
257 * @param <A> the allele type
258 * @param validAlleles the array of valid alleles.
259 * @return a new {@code EnumGene} with an randomly chosen allele from the
260 * sequence of valid alleles
261 * @throws IllegalArgumentException if the give valid alleles array is empty
262 */
263 @SafeVarargs
264 public static <A> EnumGene<A> of(final A... validAlleles) {
265 return EnumGene.of(ISeq.of(validAlleles));
266 }
267
268 }
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