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package java.util; |
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import java.util.concurrent.atomic.AtomicLong; |
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import java.util.function.DoubleConsumer; |
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import java.util.function.IntConsumer; |
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import java.util.function.LongConsumer; |
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import java.util.function.DoubleConsumer; |
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import java.util.stream.StreamSupport; |
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import java.util.stream.DoubleStream; |
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import java.util.stream.IntStream; |
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import java.util.stream.LongStream; |
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import java.util.stream.DoubleStream; |
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import java.util.stream.StreamSupport; |
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|
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/** |
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* A generator of uniform pseudorandom values applicable for use in |
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* types and ranges, but similar properties are expected to hold, at |
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* least approximately, for others as well. The <em>period</em> |
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* (length of any series of generated values before it repeats) is at |
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* least 2<sup>64</sup>. </li> |
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* least 2<sup>64</sup>. |
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* |
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* <li> Method {@link #split} constructs and returns a new |
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* <li>Method {@link #split} constructs and returns a new |
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* SplittableRandom instance that shares no mutable state with the |
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* current instance. However, with very high probability, the |
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* values collectively generated by the two objects have the same |
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* statistical properties as if the same quantity of values were |
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* generated by a single thread using a single {@code |
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* SplittableRandom} object. </li> |
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* SplittableRandom} object. |
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* |
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* <li>Instances of SplittableRandom are <em>not</em> thread-safe. |
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* They are designed to be split, not shared, across threads. For |
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* |
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* <li>This class provides additional methods for generating random |
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* streams, that employ the above techniques when used in {@code |
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* stream.parallel()} mode.</li> |
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* stream.parallel()} mode. |
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* |
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* </ul> |
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* |
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return seed += gamma; |
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} |
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// IllegalArgumentException messages |
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static final String BAD_BOUND = "bound must be positive"; |
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static final String BAD_RANGE = "bound must be greater than origin"; |
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static final String BAD_SIZE = "size must be non-negative"; |
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/** |
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* The seed generator for default constructors. |
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*/ |
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private static final AtomicLong defaultGen = new AtomicLong(initialSeed()); |
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|
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private static long initialSeed() { |
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String pp = java.security.AccessController.doPrivileged( |
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new sun.security.action.GetPropertyAction( |
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"java.util.secureRandomSeed")); |
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if (pp != null && pp.equalsIgnoreCase("true")) { |
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private static final AtomicLong defaultGen |
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= new AtomicLong(mix64(System.currentTimeMillis()) ^ |
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mix64(System.nanoTime())); |
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|
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// at end of <clinit> to survive static initialization circularity |
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static { |
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if (java.security.AccessController.doPrivileged( |
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new java.security.PrivilegedAction<Boolean>() { |
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public Boolean run() { |
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return Boolean.getBoolean("java.util.secureRandomSeed"); |
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}})) { |
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byte[] seedBytes = java.security.SecureRandom.getSeed(8); |
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long s = (long)(seedBytes[0]) & 0xffL; |
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long s = (long)seedBytes[0] & 0xffL; |
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for (int i = 1; i < 8; ++i) |
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s = (s << 8) | ((long)(seedBytes[i]) & 0xffL); |
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return s; |
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s = (s << 8) | ((long)seedBytes[i] & 0xffL); |
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defaultGen.set(s); |
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} |
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return (mix64(System.currentTimeMillis()) ^ |
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mix64(System.nanoTime())); |
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} |
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|
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// IllegalArgumentException messages |
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static final String BadBound = "bound must be positive"; |
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static final String BadRange = "bound must be greater than origin"; |
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static final String BadSize = "size must be non-negative"; |
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/* |
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* Internal versions of nextX methods used by streams, as well as |
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* the public nextX(origin, bound) methods. These exist mainly to |
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*/ |
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public int nextInt(int bound) { |
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if (bound <= 0) |
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throw new IllegalArgumentException(BadBound); |
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throw new IllegalArgumentException(BAD_BOUND); |
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// Specialize internalNextInt for origin 0 |
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int r = mix32(nextSeed()); |
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int m = bound - 1; |
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*/ |
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public int nextInt(int origin, int bound) { |
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if (origin >= bound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return internalNextInt(origin, bound); |
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} |
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*/ |
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public long nextLong(long bound) { |
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if (bound <= 0) |
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throw new IllegalArgumentException(BadBound); |
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throw new IllegalArgumentException(BAD_BOUND); |
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// Specialize internalNextLong for origin 0 |
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long r = mix64(nextSeed()); |
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long m = bound - 1; |
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*/ |
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public long nextLong(long origin, long bound) { |
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if (origin >= bound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return internalNextLong(origin, bound); |
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} |
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*/ |
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public double nextDouble(double bound) { |
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if (!(bound > 0.0)) |
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throw new IllegalArgumentException(BadBound); |
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throw new IllegalArgumentException(BAD_BOUND); |
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double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound; |
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return (result < bound) ? result : // correct for rounding |
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Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1); |
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*/ |
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public double nextDouble(double origin, double bound) { |
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if (!(origin < bound)) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return internalNextDouble(origin, bound); |
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} |
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*/ |
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public IntStream ints(long streamSize) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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return StreamSupport.intStream |
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(new RandomIntsSpliterator |
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(this, 0L, streamSize, Integer.MAX_VALUE, 0), |
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public IntStream ints(long streamSize, int randomNumberOrigin, |
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int randomNumberBound) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.intStream |
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(new RandomIntsSpliterator |
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(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
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*/ |
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public IntStream ints(int randomNumberOrigin, int randomNumberBound) { |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.intStream |
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(new RandomIntsSpliterator |
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(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
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*/ |
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public LongStream longs(long streamSize) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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return StreamSupport.longStream |
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(new RandomLongsSpliterator |
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(this, 0L, streamSize, Long.MAX_VALUE, 0L), |
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public LongStream longs(long streamSize, long randomNumberOrigin, |
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long randomNumberBound) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.longStream |
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(new RandomLongsSpliterator |
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(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
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*/ |
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public LongStream longs(long randomNumberOrigin, long randomNumberBound) { |
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if (randomNumberOrigin >= randomNumberBound) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.longStream |
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(new RandomLongsSpliterator |
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(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
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*/ |
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public DoubleStream doubles(long streamSize) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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return StreamSupport.doubleStream |
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(new RandomDoublesSpliterator |
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(this, 0L, streamSize, Double.MAX_VALUE, 0.0), |
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public DoubleStream doubles(long streamSize, double randomNumberOrigin, |
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double randomNumberBound) { |
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if (streamSize < 0L) |
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throw new IllegalArgumentException(BadSize); |
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throw new IllegalArgumentException(BAD_SIZE); |
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if (!(randomNumberOrigin < randomNumberBound)) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.doubleStream |
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(new RandomDoublesSpliterator |
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(this, 0L, streamSize, randomNumberOrigin, randomNumberBound), |
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*/ |
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public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) { |
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if (!(randomNumberOrigin < randomNumberBound)) |
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throw new IllegalArgumentException(BadRange); |
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throw new IllegalArgumentException(BAD_RANGE); |
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return StreamSupport.doubleStream |
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(new RandomDoublesSpliterator |
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(this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), |
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* approach. The long and double versions of this class are |
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* identical except for types. |
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*/ |
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static final class RandomIntsSpliterator implements Spliterator.OfInt { |
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private static final class RandomIntsSpliterator |
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implements Spliterator.OfInt { |
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final SplittableRandom rng; |
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long index; |
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final long fence; |
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/** |
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* Spliterator for long streams. |
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*/ |
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static final class RandomLongsSpliterator implements Spliterator.OfLong { |
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private static final class RandomLongsSpliterator |
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implements Spliterator.OfLong { |
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final SplittableRandom rng; |
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long index; |
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final long fence; |
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/** |
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* Spliterator for double streams. |
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*/ |
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static final class RandomDoublesSpliterator implements Spliterator.OfDouble { |
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private static final class RandomDoublesSpliterator |
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implements Spliterator.OfDouble { |
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final SplittableRandom rng; |
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long index; |
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final long fence; |