001 /*
002 * Java Genetic Algorithm Library (jenetics-4.1.0).
003 * Copyright (c) 2007-2018 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
024 import java.io.Serializable;
025 import java.util.stream.LongStream;
026
027 /**
028 * Long range class.
029 *
030 * @implSpec
031 * This class is immutable and thread-safe.
032 *
033 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
034 * @version 3.2
035 * @since 3.2
036 */
037 public final class LongRange implements Serializable {
038
039 private static final long serialVersionUID = 1L;
040
041 private final long _min;
042 private final long _max;
043
044 private LongRange(final long min, final long max) {
045 if (min > max) {
046 throw new IllegalArgumentException(format(
047 "Min greater than max: %s > %s", min, max
048 ));
049 }
050
051 _min = min;
052 _max = max;
053 }
054
055 /**
056 * Return the minimum value of the long range.
057 *
058 * @return the minimum value of the long range
059 */
060 public long getMin() {
061 return _min;
062 }
063
064 /**
065 * Return the maximum value of the long range.
066 *
067 * @return the maximum value of the long range
068 */
069 public long getMax() {
070 return _max;
071 }
072
073 /**
074 * Returns a sequential ordered {@code LongStream} from {@link #getMin()}
075 * (inclusive) to {@link #getMax()} (exclusive) by an incremental step of
076 * {@code 1}.
077 * <p>
078 * An equivalent sequence of increasing values can be produced sequentially
079 * using a {@code for} loop as follows:
080 * <pre>{@code
081 * for (long i = range.getMin(); i < range.getMax(); ++i) {
082 * ...
083 * }
084 * }</pre>
085 *
086 * @since 3.4
087 *
088 * @return a sequential {@link LongStream} for the range of {@code long}
089 * elements
090 */
091 public LongStream stream() {
092 return LongStream.range(_min, _max);
093 }
094
095 /**
096 * Create a new {@code LongRange} object with the given {@code min} and
097 * {@code max} values.
098 *
099 * @param min the lower bound of the long range
100 * @param max the upper bound of the long range
101 * @return a new {@code LongRange} object
102 * @throws IllegalArgumentException if {@code min > max}
103 */
104 public static LongRange of(final long min, final long max) {
105 return new LongRange(min, max);
106 }
107
108 /**
109 * Return a new (half open) range, which contains only the given value:
110 * {@code [value, value + 1)}.
111 *
112 * @since 4.0
113 *
114 * @param value the value of the created (half open) integer range
115 * @return a new (half open) range, which contains only the given value
116 */
117 public static LongRange of(final long value) {
118 return of(value, value + 1);
119 }
120
121 @Override
122 public int hashCode() {
123 return (int)(_min + 31*_max);
124 }
125
126 @Override
127 public boolean equals(final Object obj) {
128 return obj == this ||
129 obj instanceof LongRange &&
130 _min == ((LongRange)obj)._min &&
131 _max == ((LongRange)obj)._max;
132 }
133
134 @Override
135 public String toString() {
136 return "[" + _min + ", " + _max + "]";
137 }
138
139 }
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