/*
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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// package java.util;
import java.math.BigInteger;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
/**
* The {@code StreamableRng} interface augments the {@code Rng} interface
* to provide methods that return streams of {@code Rng} objects.
* Ideally, such a stream of objects would have the property that the
* behavior of each object is statistically independent of all the others.
* In practice, one may have to settle for some approximation to this property.
*
* A generator that implements interface {@link java.util.SplittableRng}
* may choose to use its {@code splits} method to implement the {@code rngs}
* method required by this interface.
*
* A generator that implements interface {@link java.util.JumpableRng}
* may choose to use its {@code jumps} method to implement the {@code rngs}
* method required by this interface.
*
* A generator that implements interface {@link java.util.LeapableRng}
* may choose to use its {@code leaps} method to implement the {@code rngs}
* method required by this interface.
*
* <p>An implementation of the {@code StreamableRng} interface must provide
* concrete definitions for the methods {@code nextInt()}, {@code nextLong},
* {@code period()}, and {@code rngs()}.
* Default implementations are provided for all other methods.
*
* <p>Objects that implement {@code java.util.StreamableRng} are typically
* not cryptographically secure. Consider instead using
* {@link java.security.SecureRandom} to get a cryptographically
* secure pseudo-random number generator for use by
* security-sensitive applications.
*
* @author Guy Steele
* @since 1.9
*/
import java.util.stream.Stream;
interface StreamableRng extends Rng {
/**
* Returns an effectively unlimited stream of objects, each of
* which implements the {@code Rng} interface. Ideally the
* generators in the stream will appear to be statistically
* independent. The new generators should be of the same kind
* as this generator.
*
* @implNote It is permitted to implement this method in a manner
* equivalent to {@code rngs(Long.MAX_VALUE)}.
*
* @return a stream of objects that implement the {@code Rng} interface
*/
Stream<Rng> rngs();
/**
* Returns an effectively unlimited stream of objects, each of
* which implements the {@code Rng} interface. Ideally the
* generators in the stream will appear to be statistically
* independent. The new generators should be of the same kind
* as this generator.
*
* @implNote The default implementation calls {@code rngs()} and
* then limits its length to {@code streamSize}.
*
* @param streamSize the number of generators to generate
* @return a stream of objects that implement the {@code Rng} interface
* @throws IllegalArgumentException if {@code streamSize} is
* less than zero
*/
default Stream<Rng> rngs(long streamSize) {
RngSupport.checkStreamSize(streamSize);
return rngs().limit(streamSize);
}
}