/*

 * Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved.

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

 *

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

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

 *

 * 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).

 *

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

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

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

 *

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

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

 * questions.

 */

/**

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

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

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

 *

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

 * <ul>

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

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

 * Foo one = mapper.map(a);

 * Foo two = mapper.map(a);

 *

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

 * </pre></li>

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

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

 *

 * Foo x = mapper.map(a);

 * Foo y = mapper.map(b);

 *

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

 * </pre></li>

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

 * change the mapping.</li>

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

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

 * in any specific order.</li>

 * </ul>

 *

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

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

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

 */

public interface TMapper<R, T> {

    /**

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

     *

     * @param t the input object to be mapped.

     * @return the mapped output object.

     */

    R map(T t);

}