001 /*
002 * Java Genetic Algorithm Library (jenetics-7.1.1).
003 * Copyright (c) 2007-2022 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.ext;
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.math.BigInteger;
029 import java.util.Objects;
030
031 import io.jenetics.NumericGene;
032 import io.jenetics.internal.util.Requires;
033 import io.jenetics.util.ISeq;
034 import io.jenetics.util.MSeq;
035 import io.jenetics.util.Mean;
036 import io.jenetics.util.RandomRegistry;
037
038 import io.jenetics.ext.internal.util.Randoms;
039
040 /**
041 * Numeric chromosome implementation which holds an arbitrary sized integer
042 * number.
043 *
044 * <p>This is a <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/doc-files/ValueBased.html">
045 * value-based</a> class; use of identity-sensitive operations (including
046 * reference equality ({@code ==}), identity hash code, or synchronization) on
047 * instances of {@code IntegerGene} may have unpredictable results and should
048 * be avoided.
049 *
050 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
051 * @since 3.5
052 * @version 6.0
053 */
054 public final class BigIntegerGene
055 implements
056 NumericGene<BigInteger, BigIntegerGene>,
057 Mean<BigIntegerGene>,
058 Serializable
059 {
060 @Serial
061 private static final long serialVersionUID = 1L;
062
063 private static final BigInteger TWO = BigInteger.valueOf(2);
064
065 private final BigInteger _value;
066 private final BigInteger _min;
067 private final BigInteger _max;
068
069 private BigIntegerGene(
070 final BigInteger value,
071 final BigInteger min,
072 final BigInteger max
073 ) {
074 _value = requireNonNull(value);
075 _min = requireNonNull(min);
076 _max = requireNonNull(max);
077 }
078
079 @Override
080 public BigInteger allele() {
081 return _value;
082 }
083
084 @Override
085 public BigInteger min() {
086 return _min;
087 }
088
089 @Override
090 public BigInteger max() {
091 return _max;
092 }
093
094 @Override
095 public BigIntegerGene mean(final BigIntegerGene that) {
096 final BigInteger value = _value.add(that._value).divide(TWO);
097 return of(value, _min, _max);
098 }
099
100 @Override
101 public BigIntegerGene newInstance(final Number number) {
102 return of(BigInteger.valueOf(number.longValue()), _min, _max);
103 }
104
105 @Override
106 public BigIntegerGene newInstance(final BigInteger value) {
107 return of(value, _min, _max);
108 }
109
110 @Override
111 public BigIntegerGene newInstance() {
112 return of(_min, _max);
113 }
114
115 @Override
116 public int hashCode() {
117 return hash(_value, hash(_min, hash(_max, hash(getClass()))));
118 }
119
120 @Override
121 public boolean equals(final Object obj) {
122 return obj == this ||
123 obj instanceof BigIntegerGene other &&
124 Objects.equals(other._value, _value) &&
125 Objects.equals(other._min, _min) &&
126 Objects.equals(other._max, _max);
127 }
128
129 @Override
130 public String toString() {
131 return String.format("[%s]", _value);
132 }
133
134 /* *************************************************************************
135 * Static factory methods.
136 **************************************************************************/
137
138 static ISeq<BigIntegerGene> seq(
139 final BigInteger minimum,
140 final BigInteger maximum,
141 final int length
142 ) {
143 Requires.positive(length);
144
145 final var r = random();
146
147 return MSeq.<BigIntegerGene>ofLength(length)
148 .fill(() -> new BigIntegerGene(
149 Randoms.nextBigInteger(minimum, maximum, r), minimum, maximum))
150 .toISeq();
151 }
152
153 /**
154 * Create a new random {@code BigIntegerGene} with the given value and the
155 * given range. If the {@code value} isn't within the interval [min, max],
156 * no exception is thrown. In this case the method
157 * {@link BigIntegerGene#isValid()} returns {@code false}.
158 *
159 * @param value the value of the gene.
160 * @param min the minimal valid value of this gene (inclusively).
161 * @param max the maximal valid value of this gene (exclusively).
162 * @return a new random {@code BigIntegerGene}
163 * @throws NullPointerException if one of the arguments is {@code null}
164 */
165 public static BigIntegerGene of(
166 final BigInteger value,
167 final BigInteger min,
168 final BigInteger max
169 ) {
170 return new BigIntegerGene(value, min, max);
171 }
172
173 /**
174 * Create a new random {@code BigIntegerGene}. It is guaranteed that the
175 * value of the {@code BigIntegerGene} lies in the interval [min, max].
176 *
177 * @param min the minimal valid value of this gene (inclusively).
178 * @param max the maximal valid value of this gene (exclusively).
179 * @return a new random {@code BigIntegerGene}
180 * @throws NullPointerException if one of the arguments is {@code null}
181 */
182 public static BigIntegerGene of(final BigInteger min, final BigInteger max) {
183 return of(
184 Randoms.nextBigInteger(min, max, RandomRegistry.random()),
185 min,
186 max
187 );
188 }
189
190 }
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