jdk8-mips64-public/langtools: test/tools/javac/lambda/lambdaExecution/TMapper.java@c09b7234cded

8012556: Implement lambda methods on interfaces as static
8006140: Javac NPE compiling Lambda expression on initialization expression of static field in interface
Summary: Lambdas occurring in static contexts or those not needing instance information should be generated into static methods. This has long been the case for classes. However, as a work-around to the lack of support for statics on interfaces, interface lambda methods have been generated into default methods. For lambdas in interface static contexts (fields and static methods) this causes an NPE in javac because there is no 'this'. MethodHandles now support static methods on interfaces. This changeset allows lambda methods to be generated as static interface methods. An existing bug in Hotspot (8013875) is exposed in a test when the "-esa" flag is used. This test and another test that already exposed this bug have been marked with @ignore.
Reviewed-by: mcimadamore

     1 /*

     2  * Copyright (c) 2010, 2011, 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  */

    26 /**

    27  * Given an input object maps to an appropriate output object. A mapper may

    28  * variously provide a mapping between types, object instances or keys and

    29  * values or any other form of transformation upon the input.

    30  *

    31  * <p/>All mapper implementations are expected to:

    32  * <ul>

    33  *  <li>Provide stable results such that for any {@code t} the result of two

    34  * {@code map} operations are always equivalent. ie.<pre>

    35  * Foo one = mapper.map(a);

    36  * Foo two = mapper.map(a);

    37  *

    38  * assert one.equals(two) && two.equals(one);

    39  * </pre></li>

    40  * <li>Equivalent input objects should map to equivalent output objects. ie.<pre>

    41  * assert a.equals(b);  // a and b are equivalent

    42  *

    43  * Foo x = mapper.map(a);

    44  * Foo y = mapper.map(b);

    45  *

    46  * assert x.equals(y); // their mapped results should be as equivalent.

    47  * </pre></li>

    48  * <li>The mapper should not modify the input object in any way that would

    49  * change the mapping.</li>

    50  * <li>When used for aggregate operations upon many elements mappers

    51  * should not assume that the {@code map} operation will be called upon elements

    52  * in any specific order.</li>

    53  * </ul>

    54  *

    55  * @param <R> the type of output objects from {@code map} operation. May be the

    56  * @param <T> the type of input objects provided to the {@code map} operation.

    57  * same type as {@code <T>}.

    58  */

    59 public interface TMapper<R, T> {

    61     /**

    62      * Map the provided input object to an appropriate output object.

    63      *

    64      * @param t the input object to be mapped.

    65      * @return the mapped output object.

    66      */

    67     R map(T t);

    68 }

Mercurial > jdk8-mips64-public > langtools / file revision

test/tools/javac/lambda/lambdaExecution/TMapper.java@c09b7234cded

test/tools/javac/lambda/lambdaExecution/TMapper.java