001/*
002 * Java Genetic Algorithm Library (jenetics-7.1.0).
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 */
020package io.jenetics.util;
021
022import static java.lang.String.format;
023import static io.jenetics.internal.util.Hashes.hash;
024import static io.jenetics.internal.util.SerialIO.readLong;
025import static io.jenetics.internal.util.SerialIO.writeLong;
026
027import java.io.DataInput;
028import java.io.DataOutput;
029import java.io.IOException;
030import java.io.InvalidObjectException;
031import java.io.ObjectInputStream;
032import java.io.Serial;
033import java.io.Serializable;
034import java.util.stream.LongStream;
035
036/**
037 * Long range class.
038 *
039 * @implNote
040 * This class is immutable and thread-safe.
041 *
042 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
043 * @version 6.0
044 * @since 3.2
045 */
046public final /*record*/ class LongRange implements Serializable {
047
048        @Serial
049        private static final long serialVersionUID = 2L;
050
051        private final long _min;
052        private final long _max;
053
054        private LongRange(final long min, final long max) {
055                if (min > max) {
056                        throw new IllegalArgumentException(format(
057                                "Min greater than max: %s > %s", min, max
058                        ));
059                }
060
061                _min = min;
062                _max = max;
063        }
064
065        /**
066         * Return the minimum value of the long range.
067         *
068         * @return the minimum value of the long range
069         */
070        public long min() {
071                return _min;
072        }
073
074        /**
075         * Return the maximum value of the long range.
076         *
077         * @return the maximum value of the long range
078         */
079        public long max() {
080                return _max;
081        }
082
083        /**
084         * Returns a sequential ordered {@code LongStream} from {@link #min()}
085         * (inclusive) to {@link #max()} (exclusive) by an incremental step of
086         * {@code 1}.
087         * <p>
088         * An equivalent sequence of increasing values can be produced sequentially
089         * using a {@code for} loop as follows:
090         * <pre>{@code
091         * for (long i = range.min(); i < range.max(); ++i) {
092         *     ...
093         * }
094         * }</pre>
095         *
096         * @since 3.4
097         *
098         * @return a sequential {@link LongStream} for the range of {@code long}
099         *         elements
100         */
101        public LongStream stream() {
102                return LongStream.range(_min, _max);
103        }
104
105        /**
106         * Create a new {@code LongRange} object with the given {@code min} and
107         * {@code max} values.
108         *
109         * @param min the lower bound of the long range
110         * @param max the upper bound of the long range
111         * @return a new {@code LongRange} object
112         * @throws IllegalArgumentException if {@code min > max}
113         */
114        public static LongRange of(final long min, final long max) {
115                return new LongRange(min, max);
116        }
117
118        /**
119         * Return a new (half open) range, which contains only the given value:
120         * {@code [value, value + 1)}.
121         *
122         * @since 4.0
123         *
124         * @param value the value of the created (half open) integer range
125         * @return a new (half open) range, which contains only the given value
126         */
127        public static LongRange of(final long value) {
128                return of(value, value + 1);
129        }
130
131        @Override
132        public int hashCode() {
133                return hash(_min, hash(_max, hash(getClass())));
134        }
135
136        @Override
137        public boolean equals(final Object obj) {
138                return obj == this ||
139                        obj instanceof LongRange other &&
140                        _min == other._min &&
141                        _max == other._max;
142        }
143
144        @Override
145        public String toString() {
146                return "[" + _min + ", " + _max + "]";
147        }
148
149
150        /* *************************************************************************
151         *  Java object serialization
152         * ************************************************************************/
153
154        @Serial
155        private Object writeReplace() {
156                return new SerialProxy(SerialProxy.LONG_RANGE, this);
157        }
158
159        @Serial
160        private void readObject(final ObjectInputStream stream)
161                throws InvalidObjectException
162        {
163                throw new InvalidObjectException("Serialization proxy required.");
164        }
165
166        void write(final DataOutput out) throws IOException {
167                writeLong(_min, out);
168                writeLong(_max, out);
169        }
170
171        static LongRange read(final DataInput in) throws IOException {
172                return of(readLong(in), readLong(in));
173        }
174
175}