/*

 * Copyright (c) 2010, 2013, 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

 * 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).

 *

 * 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

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 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file, and Oracle licenses the original version of this file under the BSD

 * license:

 */

/*

   Copyright 2009-2013 Attila Szegedi

*/

package jdk.dynalink.linker;

/**

 * Optional interface to be implemented by {@link GuardingTypeConverterFactory}

 * implementers. Language-specific conversions can cause increased overloaded

 * method resolution ambiguity, as many methods can become applicable because of

 * additional conversions. The static way of selecting the "most specific"

 * method will fail more often, because there will be multiple maximally

 * specific method with unrelated signatures. In these cases, language runtimes

 * can be asked to resolve the ambiguity by expressing preferences for one

 * conversion over the other.

 */

public interface ConversionComparator {

    /**

     * Enumeration of possible outcomes of comparing one conversion to another.

     */

    enum Comparison {

        /** The conversions cannot be compared. **/

        INDETERMINATE,

        /** The first conversion is better than the second one. **/

        TYPE_1_BETTER,

        /** The second conversion is better than the first one. **/

        TYPE_2_BETTER,

    }

    /**

     * Determines which of the two target types is the preferred conversion

     * target from a source type.

     * @param sourceType the source type.

     * @param targetType1 one potential target type

     * @param targetType2 another potential target type.

     * @return one of Comparison constants that establish which - if any - of

     * the target types is preferred for the conversion.

     */

    public Comparison compareConversion(Class<?> sourceType, Class<?> targetType1, Class<?> targetType2);

}