001 /*
002 * Java Genetic Algorithm Library (jenetics-6.3.0).
003 * Copyright (c) 2007-2021 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.Serializable;
033 import java.util.stream.LongStream;
034
035 /**
036 * Long range class.
037 *
038 * @implNote
039 * This class is immutable and thread-safe.
040 *
041 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
042 * @version 6.0
043 * @since 3.2
044 */
045 public final /*record*/ class LongRange implements Serializable {
046
047 private static final long serialVersionUID = 2L;
048
049 private final long _min;
050 private final long _max;
051
052 private LongRange(final long min, final long max) {
053 if (min > max) {
054 throw new IllegalArgumentException(format(
055 "Min greater than max: %s > %s", min, max
056 ));
057 }
058
059 _min = min;
060 _max = max;
061 }
062
063 /**
064 * Return the minimum value of the long range.
065 *
066 * @return the minimum value of the long range
067 */
068 public long min() {
069 return _min;
070 }
071
072 /**
073 * Return the maximum value of the long range.
074 *
075 * @return the maximum value of the long range
076 */
077 public long max() {
078 return _max;
079 }
080
081 /**
082 * Returns a sequential ordered {@code LongStream} from {@link #min()}
083 * (inclusive) to {@link #max()} (exclusive) by an incremental step of
084 * {@code 1}.
085 * <p>
086 * An equivalent sequence of increasing values can be produced sequentially
087 * using a {@code for} loop as follows:
088 * <pre>{@code
089 * for (long i = range.min(); i < range.max(); ++i) {
090 * ...
091 * }
092 * }</pre>
093 *
094 * @since 3.4
095 *
096 * @return a sequential {@link LongStream} for the range of {@code long}
097 * elements
098 */
099 public LongStream stream() {
100 return LongStream.range(_min, _max);
101 }
102
103 /**
104 * Create a new {@code LongRange} object with the given {@code min} and
105 * {@code max} values.
106 *
107 * @param min the lower bound of the long range
108 * @param max the upper bound of the long range
109 * @return a new {@code LongRange} object
110 * @throws IllegalArgumentException if {@code min > max}
111 */
112 public static LongRange of(final long min, final long max) {
113 return new LongRange(min, max);
114 }
115
116 /**
117 * Return a new (half open) range, which contains only the given value:
118 * {@code [value, value + 1)}.
119 *
120 * @since 4.0
121 *
122 * @param value the value of the created (half open) integer range
123 * @return a new (half open) range, which contains only the given value
124 */
125 public static LongRange of(final long value) {
126 return of(value, value + 1);
127 }
128
129 @Override
130 public int hashCode() {
131 return hash(_min, hash(_max, hash(getClass())));
132 }
133
134 @Override
135 public boolean equals(final Object obj) {
136 return obj == this ||
137 obj instanceof LongRange &&
138 _min == ((LongRange)obj)._min &&
139 _max == ((LongRange)obj)._max;
140 }
141
142 @Override
143 public String toString() {
144 return "[" + _min + ", " + _max + "]";
145 }
146
147
148 /* *************************************************************************
149 * Java object serialization
150 * ************************************************************************/
151
152 private Object writeReplace() {
153 return new Serial(Serial.LONG_RANGE, this);
154 }
155
156 private void readObject(final ObjectInputStream stream)
157 throws InvalidObjectException
158 {
159 throw new InvalidObjectException("Serialization proxy required.");
160 }
161
162 void write(final DataOutput out) throws IOException {
163 writeLong(_min, out);
164 writeLong(_max, out);
165 }
166
167 static LongRange read(final DataInput in) throws IOException {
168 return of(readLong(in), readLong(in));
169 }
170
171 }
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