1 /*

     2  * Copyright (c) 2011, 2012, 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 /**

    26  * <em>Functional interfaces</em> provide typing for lambda expressions. Each

    27  * functional interface provides a single abstract method to which the lambda

    28  * expression's parameter and return types are matched.

    29  *

    30  * <p>The interfaces in this package are all functional interfaces used with the

    31  * collections and streams frameworks. The operation identified by each

    32  * interface is generally applied to a collection or stream of objects.

    33  *

    34  * <p>All functional interface implementations are expected to ensure that:

    35  * <ul>

    36  * <li>When used for aggregate operations upon many elements it should not be

    37  * assumed that the operation will be called upon elements in any specific order.

    38  * </li>

    39  * <li>{@code null} values are accepted and returned by these functional

    40  * interfaces according to the constraints of the specification in which the

    41  * functional interfaces are used. The functional interfaces themselves do not

    42  * constrain or mandate use of {@code null} values. Most usages of the

    43  * functional interfaces will define the role, if any, of {@code null} for that

    44  * context.

    45  * </li>

    46  * </ul>

    47  */

    48 package java.util.function;