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

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 * 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,

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 *

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package com.sun.source.doctree;

/**

 * A visitor of trees, in the style of the visitor design pattern.

 * Classes implementing this interface are used to operate

 * on a tree when the kind of tree is unknown at compile time.

 * When a visitor is passed to an tree's {@link DocTree#accept

 * accept} method, the <code>visit<i>Xyz</i></code> method most applicable

 * to that tree is invoked.

 *

 * <p> Classes implementing this interface may or may not throw a

 * {@code NullPointerException} if the additional parameter {@code p}

 * is {@code null}; see documentation of the implementing class for

 * details.

 *

 * <p> <b>WARNING:</b> It is possible that methods will be added to

 * this interface to accommodate new, currently unknown, doc comment

 * structures added to future versions of the Java™ programming

 * language.  Therefore, visitor classes directly implementing this

 * interface may be source incompatible with future versions of the

 * platform.

 *

 * @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.

 *

 * @since 1.8

 */

public interface DocTreeVisitor<R,P> {

    /**

     * Visits an AttributeTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitAttribute(AttributeTree node, P p);

    /**

     * Visits an AuthorTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitAuthor(AuthorTree node, P p);

    /**

     * Visits a CommentTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitComment(CommentTree node, P p);

    /**

     * Visits a DeprecatedTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitDeprecated(DeprecatedTree node, P p);

    /**

     * Visits a DocCommentTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitDocComment(DocCommentTree node, P p);

    /**

     * Visits a DocRootTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitDocRoot(DocRootTree node, P p);

    /**

     * Visits a DocTypeTree node.

     *

     * @implSpec Visits a {@code DocTypeTree} node

     * by calling {@code visitOther(node, p)}.

     *

     * @param node the node being visited

     * @param p    a parameter value

     * @return a result value

     * @since 10

     */

    default R visitDocType(DocTypeTree node, P p) {

        return visitOther(node, p);

    }

    /**

     * Visits an EndElementTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitEndElement(EndElementTree node, P p);

    /**

     * Visits an EntityTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitEntity(EntityTree node, P p);

    /**

     * Visits an ErroneousTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitErroneous(ErroneousTree node, P p);

    /**

     * Visits a HiddenTree node.

     *

     * @implSpec Visits a {@code HiddenTree} node

     * by calling {@code visitOther(node, p)}.

     *

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     *

     * @since 9

     */

    default R visitHidden(HiddenTree node, P p)  {

        return visitOther(node, p);

    }

    /**

     * Visits an IdentifierTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitIdentifier(IdentifierTree node, P p);

    /**

     * Visits an IndexTree node.

     *

     * @implSpec Visits an {@code IndexTree} node

     * by calling {@code visitOther(node, p)}.

     *

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     *

     * @since 9

     */

    default R visitIndex(IndexTree node, P p) {

        return visitOther(node, p);

    }

    /**

     * Visits an InheritDocTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitInheritDoc(InheritDocTree node, P p);

    /**

     * Visits a LinkTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitLink(LinkTree node, P p);

    /**

     * Visits an LiteralTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitLiteral(LiteralTree node, P p);

    /**

     * Visits a ParamTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitParam(ParamTree node, P p);

    /**

     * Visits a ProvidesTree node.

     *

     * @implSpec Visits a {@code ProvidesTree} node

     * by calling {@code visitOther(node, p)}.

     *

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     *

     * @since 9

     */

    default R visitProvides(ProvidesTree node, P p) {

        return visitOther(node, p);

    }

    /**

     * Visits a ReferenceTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitReference(ReferenceTree node, P p);

    /**

     * Visits a ReturnTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitReturn(ReturnTree node, P p);

    /**

     * Visits a SeeTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitSee(SeeTree node, P p);

    /**

     * Visits a SerialTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitSerial(SerialTree node, P p);

    /**

     * Visits a SerialDataTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitSerialData(SerialDataTree node, P p);

    /**

     * Visits a SerialFieldTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitSerialField(SerialFieldTree node, P p);

    /**

     * Visits a SinceTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitSince(SinceTree node, P p);

    /**

     * Visits a StartElementTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitStartElement(StartElementTree node, P p);

    /**

     * Visits a SummaryTree node.

     *

     * @implSpec Visits a {@code SummaryTree} node

     * by calling {@code visitOther(node, p)}.

     *

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     * @since 10

     */

    default R visitSummary(SummaryTree node, P p) {

        return visitOther(node, p);

    }

    /**

     * Visits a TextTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitText(TextTree node, P p);

    /**

     * Visits a ThrowsTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitThrows(ThrowsTree node, P p);

    /**

     * Visits an UnknownBlockTagTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitUnknownBlockTag(UnknownBlockTagTree node, P p);

    /**

     * Visits an UnknownInlineTagTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitUnknownInlineTag(UnknownInlineTagTree node, P p);

    /**

     * Visits a UsesTree node.

     *

     * @implSpec Visits a {@code UsesTree} node

     * by calling {@code visitOther(node, p)}.

     *

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     *

     * @since 9

     */

    default R visitUses(UsesTree node, P p) {

        return visitOther(node, p);

    }

    /**

     * Visits a ValueTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitValue(ValueTree node, P p);

    /**

     * Visits a VersionTreeTree node.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitVersion(VersionTree node, P p);

    /**

     * Visits an unknown type of DocTree node.

     * This can occur if the set of tags evolves and new kinds

     * of nodes are added to the {@code DocTree} hierarchy.

     * @param node the node being visited

     * @param p a parameter value

     * @return a result value

     */

    R visitOther(DocTree node, P p);

}