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 * 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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package javax.lang.model.util;

import javax.lang.model.element.*;

import static javax.lang.model.element.ElementKind.*;

import javax.annotation.processing.SupportedSourceVersion;

import static javax.lang.model.SourceVersion.*;

import javax.lang.model.SourceVersion;

/**

 * A visitor of program elements based on their {@linkplain

 * ElementKind kind} with default behavior appropriate for the {@link

 * SourceVersion#RELEASE_6 RELEASE_6} source version.  For {@linkplain

 * Element elements} <tt><i>XYZ</i></tt> that may have more than one

 * kind, the <tt>visit<i>XYZ</i></tt> methods in this class delegate

 * to the <tt>visit<i>XYZKind</i></tt> method corresponding to the

 * first argument's kind.  The <tt>visit<i>XYZKind</i></tt> methods

 * call {@link #defaultAction defaultAction}, passing their arguments

 * to {@code defaultAction}'s corresponding parameters.

 *

 * <p> Methods in this class may be overridden subject to their

 * general contract.  Note that annotating methods in concrete

 * subclasses with {@link java.lang.Override @Override} will help

 * ensure that methods are overridden as intended.

 *

 * <p> <b>WARNING:</b> The {@code ElementVisitor} interface

 * implemented by this class may have methods added to it or the

 * {@code ElementKind} {@code enum} used in this case may have

 * constants added to it in the future to accommodate new, currently

 * unknown, language structures added to future versions of the

 * Java™ programming language.  Therefore, methods whose names

 * begin with {@code "visit"} may be added to this class in the

 * future; to avoid incompatibilities, classes which extend this class

 * should not declare any instance methods with names beginning with

 * {@code "visit"}.

 *

 * <p>When such a new visit method is added, the default

 * implementation in this class will be to call the {@link

 * #visitUnknown visitUnknown} method.  A new abstract element kind

 * visitor class will also be introduced to correspond to the new

 * language level; this visitor will have different default behavior

 * for the visit method in question.  When the new visitor is

 * introduced, all or portions of this visitor may be deprecated.

 *

 * @param <R> the return type of this visitor's methods.  Use {@link

 *            Void} for visitors that do not need to return results.

 * @param <P> the type of the additional parameter to this visitor's

 *            methods.  Use {@code Void} for visitors that do not need an

 *            additional parameter.

 *

 * @author Joseph D. Darcy

 * @author Scott Seligman

 * @author Peter von der Ahé

 *

 * @see ElementKindVisitor7

 * @since 1.6

 */

@SupportedSourceVersion(RELEASE_6)

public class ElementKindVisitor6<R, P>

                  extends SimpleElementVisitor6<R, P> {

    /**

     * Constructor for concrete subclasses; uses {@code null} for the

     * default value.

     */

    protected ElementKindVisitor6() {

        super(null);

    }

    /**

     * Constructor for concrete subclasses; uses the argument for the

     * default value.

     *

     * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}

     */

    protected ElementKindVisitor6(R defaultValue) {

        super(defaultValue);

    }

    /**

     * {@inheritDoc}

     *

     * The element argument has kind {@code PACKAGE}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  {@inheritDoc}

     */

    @Override

    public R visitPackage(PackageElement e, P p) {

        assert e.getKind() == PACKAGE: "Bad kind on PackageElement";

        return defaultAction(e, p);

    }

    /**

     * Visits a type element, dispatching to the visit method for the

     * specific {@linkplain ElementKind kind} of type, {@code

     * ANNOTATION_TYPE}, {@code CLASS}, {@code ENUM}, or {@code

     * INTERFACE}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of the kind-specific visit method

     */

    @Override

    public R visitType(TypeElement e, P p) {

        ElementKind k = e.getKind();

        switch(k) {

        case ANNOTATION_TYPE:

            return visitTypeAsAnnotationType(e, p);

        case CLASS:

            return visitTypeAsClass(e, p);

        case ENUM:

            return visitTypeAsEnum(e, p);

        case INTERFACE:

            return visitTypeAsInterface(e, p);

        default:

            throw new AssertionError("Bad kind " + k + " for TypeElement" + e);

        }

    }

    /**

     * Visits an {@code ANNOTATION_TYPE} type element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitTypeAsAnnotationType(TypeElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a {@code CLASS} type element by calling {@code

     * defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitTypeAsClass(TypeElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits an {@code ENUM} type element by calling {@code

     * defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitTypeAsEnum(TypeElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits an {@code INTERFACE} type element by calling {@code

     * defaultAction}.

     *.

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitTypeAsInterface(TypeElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a variable element, dispatching to the visit method for

     * the specific {@linkplain ElementKind kind} of variable, {@code

     * ENUM_CONSTANT}, {@code EXCEPTION_PARAMETER}, {@code FIELD},

     * {@code LOCAL_VARIABLE}, {@code PARAMETER}, or {@code RESOURCE_VARIABLE}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of the kind-specific visit method

     */

    @Override

    public R visitVariable(VariableElement e, P p) {

        ElementKind k = e.getKind();

        switch(k) {

        case ENUM_CONSTANT:

            return visitVariableAsEnumConstant(e, p);

        case EXCEPTION_PARAMETER:

            return visitVariableAsExceptionParameter(e, p);

        case FIELD:

            return visitVariableAsField(e, p);

        case LOCAL_VARIABLE:

            return visitVariableAsLocalVariable(e, p);

        case PARAMETER:

            return visitVariableAsParameter(e, p);

        case RESOURCE_VARIABLE:

            return visitVariableAsResourceVariable(e, p);

        default:

            throw new AssertionError("Bad kind " + k + " for VariableElement" + e);

        }

    }

    /**

     * Visits an {@code ENUM_CONSTANT} variable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitVariableAsEnumConstant(VariableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits an {@code EXCEPTION_PARAMETER} variable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitVariableAsExceptionParameter(VariableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a {@code FIELD} variable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitVariableAsField(VariableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a {@code LOCAL_VARIABLE} variable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitVariableAsLocalVariable(VariableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a {@code PARAMETER} variable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitVariableAsParameter(VariableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a {@code RESOURCE_VARIABLE} variable element by calling

     * {@code visitUnknown}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code visitUnknown}

     *

     * @since 1.7

     */

    public R visitVariableAsResourceVariable(VariableElement e, P p) {

        return visitUnknown(e, p);

    }

    /**

     * Visits an executable element, dispatching to the visit method

     * for the specific {@linkplain ElementKind kind} of executable,

     * {@code CONSTRUCTOR}, {@code INSTANCE_INIT}, {@code METHOD}, or

     * {@code STATIC_INIT}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of the kind-specific visit method

     */

    @Override

    public R visitExecutable(ExecutableElement e, P p) {

        ElementKind k = e.getKind();

        switch(k) {

        case CONSTRUCTOR:

            return visitExecutableAsConstructor(e, p);

        case INSTANCE_INIT:

            return visitExecutableAsInstanceInit(e, p);

        case METHOD:

            return visitExecutableAsMethod(e, p);

        case STATIC_INIT:

            return visitExecutableAsStaticInit(e, p);

        default:

            throw new AssertionError("Bad kind " + k + " for ExecutableElement" + e);

        }

    }

    /**

     * Visits a {@code CONSTRUCTOR} executable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitExecutableAsConstructor(ExecutableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits an {@code INSTANCE_INIT} executable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitExecutableAsInstanceInit(ExecutableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a {@code METHOD} executable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitExecutableAsMethod(ExecutableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * Visits a {@code STATIC_INIT} executable element by calling

     * {@code defaultAction}.

     *

     * @param e the element to visit

     * @param p a visitor-specified parameter

     * @return  the result of {@code defaultAction}

     */

    public R visitExecutableAsStaticInit(ExecutableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * {@inheritDoc}

     *

     * The element argument has kind {@code TYPE_PARAMETER}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  {@inheritDoc}

     */

    @Override

    public R visitTypeParameter(TypeParameterElement e, P p) {

        assert e.getKind() == TYPE_PARAMETER: "Bad kind on TypeParameterElement";

        return defaultAction(e, p);

    }

}