1 /*

     2  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.

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

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

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

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

    10  *

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

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

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

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

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package java.util.stream;

    26 

    27 /**

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

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

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

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

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

    33  * {@code Consumer}, etc.

    34  *

    35  * @apiNote

    36  * This enum is used by implementations to determine compatibility between

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

    38  * with the input shape of the next operation).

    39  *

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

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

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

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

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

    45  * primitive type.

    46  *

    47  * @since 1.8

    48  */

    49 enum StreamShape {

    50     /**

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

    52      * that are object references.

    53      */

    54     REFERENCE,

    55     /**

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

    57      * that are {@code int} values.

    58      */

    59     INT_VALUE,

    60     /**

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

    62      * that are {@code long} values.

    63      */

    64     LONG_VALUE,

    65     /**

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

    67      * elements that are {@code double} values.

    68      */

    69     DOUBLE_VALUE

    70 }