/*

 * 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.

 *

 * 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.

 *

 */

/*

 * @test

 * @bug 4509267

 * @summary generics: parametric exception type versus overriding

 * @author gafter

 *

 * @compile  ParametricException.java

 */

import java.io.*;

abstract class AChurchBoolean {

    public abstract <Return, Parameter, Throws extends Throwable>

    Return accept(IVisitor<Return, Parameter, Throws> visitor, Parameter parameter) throws Throws;

    public interface IVisitor<Return, Parameter, Throws extends Throwable> {

        public Return caseTrue(Parameter parameter) throws Throws;

        public Return caseFalse(Parameter parameter) throws Throws;

    }

}

class TrueChurchBoolean extends AChurchBoolean {

    private static TrueChurchBoolean instance = new TrueChurchBoolean();

    private TrueChurchBoolean() {}

    public static TrueChurchBoolean singleton() {

        return instance;

    }

    public <Return, Parameter, Throws extends Throwable>

    Return accept(IVisitor<Return, Parameter, Throws> visitor, Parameter parameter) throws Throws {

        return visitor.caseTrue(parameter);

    }

}

class FalseChurchBoolean extends AChurchBoolean {

    private static FalseChurchBoolean instance = new FalseChurchBoolean();

    private FalseChurchBoolean() {}

    public static FalseChurchBoolean singleton() {

        return instance;

    }

    public <Return, Parameter, Throws extends Throwable>

    Return accept(IVisitor<Return, Parameter, Throws> visitor, Parameter parameter) throws Throws {

        return visitor.caseFalse(parameter);

    }

}

class Pair<T,U> {

    private T first;

    private U second;

    Pair(T first, U second) {

        this.first = first;

        this.second = second;

    }

    T getFirst() {

        return first;

    }

    U getSecond() {

        return second;

    }

}

// Perhaps a bit of a toy example, but relevant nonetheless.

class ChurchBooleanTest {

    private AChurchBoolean bool;

    public ChurchBooleanTest(AChurchBoolean bool) {

        this.bool = bool;

    }

    public AChurchBoolean readIf(File file, byte[] output) throws IOException {

        return bool.accept(new AChurchBoolean.IVisitor<AChurchBoolean, Pair<File, byte[]>, IOException>() {

            public AChurchBoolean caseTrue(Pair<File, byte[]> parameter) throws IOException {

                FileInputStream input = new FileInputStream(parameter.getFirst()); // throws

                input.read(parameter.getSecond()); // throws

                input.close(); // throws

                return TrueChurchBoolean.singleton();

            }

            public AChurchBoolean caseFalse(Pair<File, byte[]> parameter) throws IOException {

                return FalseChurchBoolean.singleton();

            }

        }, new Pair<File, byte[]>(file, output));

    }

}