001 /*
002 * Java Genetic Algorithm Library (jenetics-8.0.0).
003 * Copyright (c) 2007-2024 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.util.Objects.requireNonNull;
023 import static io.jenetics.internal.util.Hashes.hash;
024 import static io.jenetics.util.RandomRegistry.random;
025
026 import java.io.Serial;
027 import java.io.Serializable;
028 import java.util.Objects;
029
030 import io.jenetics.util.CharSeq;
031 import io.jenetics.util.ISeq;
032 import io.jenetics.util.IntRange;
033 import io.jenetics.util.MSeq;
034 import io.jenetics.util.RandomRegistry;
035
036 /**
037 * Character gene implementation.
038 *
039 * <p>This is a <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/doc-files/ValueBased.html">
040 * value-based</a> class; use of identity-sensitive operations (including
041 * reference equality ({@code ==}), identity hash code, or synchronization) on
042 * instances of {@code CharacterGene} may have unpredictable results and should
043 * be avoided.
044 *
045 * @see CharacterChromosome
046 *
047 * @implNote
048 * This class is immutable and thread-safe.
049 *
050 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
051 * @since 1.0
052 * @version 6.0
053 */
054 public final class CharacterGene
055 implements
056 Gene<Character, CharacterGene>,
057 Comparable<CharacterGene>,
058 Serializable
059 {
060 @Serial
061 private static final long serialVersionUID = 3L;
062
063 /**
064 * The default character set used by this gene.
065 */
066 public static final CharSeq DEFAULT_CHARACTERS = new CharSeq("""
067 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ \
068 !"$%&/()=?`{[]}\\+~*#';.:,-_<>|@^'"""
069 );
070
071 private final char _allele;
072 private final CharSeq _validCharacters;
073
074 private CharacterGene(final CharSeq chars, final int index) {
075 _allele = chars.get(index);
076 _validCharacters = chars;
077 }
078
079 /**
080 * Create a new character gene from the given {@code character} and the
081 * given set of valid characters.
082 *
083 * @param allele the char this gene represents
084 * @param validChars the set of valid characters.
085 * @throws NullPointerException if one of the arguments is {@code null}.
086 */
087 private CharacterGene(final char allele, final CharSeq validChars) {
088 _allele = allele;
089 _validCharacters = requireNonNull(validChars);
090 }
091
092 @Override
093 public boolean isValid() {
094 return _validCharacters.contains(_allele);
095 }
096
097 @Override
098 public Character allele() {
099 return _allele;
100 }
101
102 /**
103 * Return the {@code char} value of this character gene.
104 *
105 * @return the {@code char} value.
106 */
107 public char charValue() {
108 return _allele;
109 }
110
111 /**
112 * Test, if the given character is valid.
113 *
114 * @param allele The character to test.
115 * @return true if the character is valid, false otherwise.
116 */
117 public boolean isValidCharacter(final Character allele) {
118 return _validCharacters.contains(allele);
119 }
120
121 /**
122 * Return a (unmodifiable) set of valid characters.
123 *
124 * @return the {@link CharSeq} of valid characters.
125 */
126 public CharSeq validChars() {
127 return _validCharacters;
128 }
129
130 /**
131 * @see java.lang.Character#compareTo(java.lang.Character)
132 * @param that The other gene to compare.
133 * @return value 0 if the argument Character is equal to this Character;
134 * a value less than 0 if this Character is numerically less than
135 * the Character argument; and a value greater than 0 if this
136 * Character is numerically greater than the Character argument
137 * (unsigned comparison). Note that this is strictly a numerical
138 * comparison; it is not local-dependent.
139 */
140 @Override
141 public int compareTo(final CharacterGene that) {
142 return Character.compare(_allele, that._allele);
143 }
144
145 @Override
146 public int hashCode() {
147 return hash(_allele, hash(_validCharacters));
148 }
149
150 @Override
151 public boolean equals(final Object obj) {
152 return obj == this ||
153 obj instanceof CharacterGene other &&
154 other._allele == _allele &&
155 Objects.equals(other._validCharacters, _validCharacters);
156 }
157
158 @Override
159 public String toString() {
160 return Character.toString(_allele);
161 }
162
163
164 /* *************************************************************************
165 * Factory methods
166 * ************************************************************************/
167
168 @Override
169 public CharacterGene newInstance() {
170 return of(_validCharacters);
171 }
172
173 /**
174 * Create a new character gene from the given character. If the character
175 * is not within the {@link #validChars()}, an invalid gene will be
176 * created.
177 *
178 * @param allele the character value of the created gene.
179 * @return a new character gene.
180 * @throws NullPointerException if the given {@code character} is
181 * {@code null}.
182 */
183 @Override
184 public CharacterGene newInstance(final Character allele) {
185 return of(allele, _validCharacters);
186 }
187
188
189 /* *************************************************************************
190 * Static object creation methods
191 * ************************************************************************/
192
193 /**
194 * Create a new CharacterGene with a randomly chosen character from the
195 * set of valid characters.
196 *
197 * @param validCharacters the valid characters for this gene.
198 * @return a new valid, <em>random</em> gene,
199 * @throws NullPointerException if the {@code validCharacters} are
200 * {@code null}.
201 */
202 public static CharacterGene of(final CharSeq validCharacters) {
203 return new CharacterGene(
204 validCharacters,
205 RandomRegistry.random().nextInt(validCharacters.length())
206 );
207 }
208
209 /**
210 * Create a new character gene from the given character. If the character
211 * is not within the {@link #DEFAULT_CHARACTERS}, an invalid gene will be
212 * created.
213 *
214 * @param allele the character value of the created gene.
215 * @return a new character gene.
216 */
217 public static CharacterGene of(final char allele) {
218 return new CharacterGene(allele, DEFAULT_CHARACTERS);
219 }
220
221 /**
222 * Create a new random character gene, chosen from the
223 * {@link #DEFAULT_CHARACTERS}.
224 *
225 * @return a new random character gene.
226 */
227 public static CharacterGene of() {
228 return new CharacterGene(
229 DEFAULT_CHARACTERS,
230 RandomRegistry.random().nextInt(DEFAULT_CHARACTERS.length())
231 );
232 }
233
234 /**
235 * Create a new CharacterGene from the give character.
236 *
237 * @param allele The allele.
238 * @param validCharacters the valid characters for the new gene
239 * @return a new {@code CharacterGene} with the given parameter
240 * @throws NullPointerException if one of the arguments is {@code null}.
241 * @throws IllegalArgumentException if the {@code validCharacters} are empty.
242 */
243 public static CharacterGene of(
244 final char allele,
245 final CharSeq validCharacters
246 ) {
247 return new CharacterGene(allele, validCharacters);
248 }
249
250 static ISeq<CharacterGene> seq(
251 final CharSeq chars,
252 final IntRange lengthRange
253 ) {
254 final var random = random();
255 final var length = random.nextInt(lengthRange.min(), lengthRange.max());
256
257 return MSeq.<CharacterGene>ofLength(length)
258 .fill(() -> new CharacterGene(chars, random.nextInt(chars.length())))
259 .toISeq();
260 }
261
262 }
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