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.util;
021
022 import static java.lang.String.format;
023 import static io.jenetics.internal.util.Hashes.hash;
024 import static io.jenetics.internal.util.SerialIO.readLong;
025 import static io.jenetics.internal.util.SerialIO.writeLong;
026
027 import java.io.DataInput;
028 import java.io.DataOutput;
029 import java.io.IOException;
030 import java.io.InvalidObjectException;
031 import java.io.ObjectInputStream;
032 import java.io.Serial;
033 import java.io.Serializable;
034 import java.util.Optional;
035 import java.util.stream.LongStream;
036
037 /**
038 * Long range class.
039 *
040 * @implNote
041 * This class is immutable and thread-safe.
042 *
043 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
044 * @version 6.0
045 * @since 3.2
046 */
047 public final /*record*/ class LongRange implements Serializable {
048
049 @Serial
050 private static final long serialVersionUID = 2L;
051
052 private final long _min;
053 private final long _max;
054
055 private LongRange(final long min, final long max) {
056 if (min > max) {
057 throw new IllegalArgumentException(format(
058 "Min greater than max: %s > %s", min, max
059 ));
060 }
061
062 _min = min;
063 _max = max;
064 }
065
066 /**
067 * Return the minimum value of the long range.
068 *
069 * @return the minimum value of the long range
070 */
071 public long min() {
072 return _min;
073 }
074
075 /**
076 * Return the maximum value of the long range.
077 *
078 * @return the maximum value of the long range
079 */
080 public long max() {
081 return _max;
082 }
083
084 /**
085 * Checks whether the given {@code value} is within the range
086 * {@code [min, max)}.
087 *
088 * @since 8.0
089 *
090 * @param value the value to check
091 * @return {@code true} if the {@code value} is with the range
092 * {@code [min, max)}, {@code false} otherwise
093 */
094 public boolean contains(final long value) {
095 return value >= _min && value < _max;
096 }
097
098 /**
099 * Return the intersection of {@code this} range with the {@code other}.
100 *
101 * @since 8.0
102 *
103 * @param other the intersection range or {@link Optional#empty()} if there
104 * is none
105 * @return the range intersection
106 */
107 public Optional<LongRange> intersect(final LongRange other) {
108 if (_max <= other._min || _min >= other._max) {
109 return Optional.empty();
110 } else {
111 return Optional.of(
112 LongRange.of(
113 Math.max(_min, other._min),
114 Math.min(_max, other._max)
115 )
116 );
117 }
118 }
119
120 /**
121 * Returns a sequential ordered {@code LongStream} from {@link #min()}
122 * (inclusive) to {@link #max()} (exclusive) by an incremental step of
123 * {@code 1}.
124 * <p>
125 * An equivalent sequence of increasing values can be produced sequentially
126 * using a {@code for} loop as follows:
127 * {@snippet lang="java":
128 * for (long i = range.min(); i < range.max(); ++i) {
129 * // ...
130 * }
131 * }
132 *
133 * @since 3.4
134 *
135 * @return a sequential {@link LongStream} for the range of {@code long}
136 * elements
137 */
138 public LongStream stream() {
139 return LongStream.range(_min, _max);
140 }
141
142 /**
143 * Create a new {@code LongRange} object with the given {@code min} and
144 * {@code max} values.
145 *
146 * @param min the lower bound of the long range
147 * @param max the upper bound of the long range
148 * @return a new {@code LongRange} object
149 * @throws IllegalArgumentException if {@code min > max}
150 */
151 public static LongRange of(final long min, final long max) {
152 return new LongRange(min, max);
153 }
154
155 /**
156 * Return a new (half-open) range, which contains only the given value:
157 * {@code [value, value + 1)}.
158 *
159 * @since 4.0
160 *
161 * @param value the value of the created (half-open) integer range
162 * @return a new (half-open) range, which contains only the given value
163 */
164 public static LongRange of(final long value) {
165 return of(value, value + 1);
166 }
167
168 @Override
169 public int hashCode() {
170 return hash(_min, hash(_max, hash(getClass())));
171 }
172
173 @Override
174 public boolean equals(final Object obj) {
175 return obj == this ||
176 obj instanceof LongRange other &&
177 _min == other._min &&
178 _max == other._max;
179 }
180
181 @Override
182 public String toString() {
183 return "[" + _min + ", " + _max + "]";
184 }
185
186
187 /* *************************************************************************
188 * Java object serialization
189 * ************************************************************************/
190
191 @Serial
192 private Object writeReplace() {
193 return new SerialProxy(SerialProxy.LONG_RANGE, this);
194 }
195
196 @Serial
197 private void readObject(final ObjectInputStream stream)
198 throws InvalidObjectException
199 {
200 throw new InvalidObjectException("Serialization proxy required.");
201 }
202
203 void write(final DataOutput out) throws IOException {
204 writeLong(_min, out);
205 writeLong(_max, out);
206 }
207
208 static LongRange read(final DataInput in) throws IOException {
209 return of(readLong(in), readLong(in));
210 }
211
212 }
|