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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

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 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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package java.util;

import java.util.Rng;

import java.util.RngSupport;

import java.util.stream.Stream;

/**

 * 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

 */

public 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);

    }

}