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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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 * accompanied this code).

 *

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package javax.lang.model.util;

import javax.lang.model.element.*;

import javax.annotation.processing.SupportedSourceVersion;

import javax.lang.model.SourceVersion;

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

/**

 * A simple visitor of program elements with default behavior

 * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}

 * source version.

 *

 * Visit methods corresponding to {@code RELEASE_6} language

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

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

 *

 * For constructs introduced in {@code RELEASE_7} and later, {@code

 * visitUnknown} is called instead.

 *

 * <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 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 simple element 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 {@code 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 SimpleElementVisitor7

 * @see SimpleElementVisitor8

 * @see SimpleElementVisitor9

 * @since 1.6

 * @deprecated Release 6 is obsolete; update to a visitor for a newer

 * release level.

 */

@Deprecated

@SupportedSourceVersion(RELEASE_6)

public class SimpleElementVisitor6<R, P> extends AbstractElementVisitor6<R, P> {

    /**

     * Default value to be returned; {@link #defaultAction

     * defaultAction} returns this value unless the method is

     * overridden.

     */

    protected final R DEFAULT_VALUE;

    /**

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

     * default value.

     */

    protected SimpleElementVisitor6(){

        DEFAULT_VALUE = null;

    }

    /**

     * Constructor for concrete subclasses; uses the argument for the

     * default value.

     *

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

     */

    protected SimpleElementVisitor6(R defaultValue){

        DEFAULT_VALUE = defaultValue;

    }

    /**

     * The default action for visit methods.  The implementation in

     * this class just returns {@link #DEFAULT_VALUE}; subclasses will

     * commonly override this method.

     *

     * @param e the element to process

     * @param p a visitor-specified parameter

     * @return {@code DEFAULT_VALUE} unless overridden

     */

    protected R defaultAction(Element e, P p) {

        return DEFAULT_VALUE;

    }

    /**

     * {@inheritDoc} This implementation calls {@code defaultAction}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of {@code defaultAction}

     */

    public R visitPackage(PackageElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * {@inheritDoc} This implementation calls {@code defaultAction}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of {@code defaultAction}

     */

    public R visitType(TypeElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * {@inheritDoc}

     *

     * This implementation calls {@code defaultAction}, unless the

     * element is a {@code RESOURCE_VARIABLE} in which case {@code

     * visitUnknown} is called.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of {@code defaultAction} or {@code visitUnknown}

     */

    public R visitVariable(VariableElement e, P p) {

        if (e.getKind() != ElementKind.RESOURCE_VARIABLE)

            return defaultAction(e, p);

        else

            return visitUnknown(e, p);

    }

    /**

     * {@inheritDoc} This implementation calls {@code defaultAction}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of {@code defaultAction}

     */

    public R visitExecutable(ExecutableElement e, P p) {

        return defaultAction(e, p);

    }

    /**

     * {@inheritDoc} This implementation calls {@code defaultAction}.

     *

     * @param e {@inheritDoc}

     * @param p {@inheritDoc}

     * @return  the result of {@code defaultAction}

     */

    public R visitTypeParameter(TypeParameterElement e, P p) {

        return defaultAction(e, p);

    }

}