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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

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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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 * 2 along with this work; if not, write to the Free Software Foundation,

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 *

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 */

package java.util.stream;

/**

 * An enum describing the known shape specializations for stream abstractions.

 * Each will correspond to a specific subinterface of {@link BaseStream}

 * (e.g., {@code REFERENCE} corresponds to {@code Stream}, {@code INT_VALUE}

 * corresponds to {@code IntStream}).  Each may also correspond to

 * specializations of value-handling abstractions such as {@code Spliterator},

 * {@code Consumer}, etc.

 *

 * @apiNote

 * This enum is used by implementations to determine compatibility between

 * streams and operations (i.e., if the output shape of a stream is compatible

 * with the input shape of the next operation).

 *

 * <p>Some APIs require you to specify both a generic type and a stream shape

 * for input or output elements, such as {@link TerminalOp} which has both

 * generic type parameters for its input types, and a getter for the

 * input shape.  When representing primitive streams in this way, the

 * generic type parameter should correspond to the wrapper type for that

 * primitive type.

 *

 * @since 1.8

 */

enum StreamShape {

    /**

     * The shape specialization corresponding to {@code Stream} and elements

     * that are object references.

     */

    REFERENCE,

    /**

     * The shape specialization corresponding to {@code IntStream} and elements

     * that are {@code int} values.

     */

    INT_VALUE,

    /**

     * The shape specialization corresponding to {@code LongStream} and elements

     * that are {@code long} values.

     */

    LONG_VALUE,

    /**

     * The shape specialization corresponding to {@code DoubleStream} and

     * elements that are {@code double} values.

     */

    DOUBLE_VALUE

}