jdk8-mips64-public/langtools: src/share/classes/com/sun/source/util/TreePathScanner.java@9a66ca7c79fa

     1 /*

     2  * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.

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

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

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

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    26 package com.sun.source.util;

    28 import com.sun.source.tree.*;

    30 /**

    31  * A TreeVisitor that visits all the child tree nodes, and provides

    32  * support for maintaining a path for the parent nodes.

    33  * To visit nodes of a particular type, just override the

    34  * corresponding visitorXYZ method.

    35  * Inside your method, call super.visitXYZ to visit descendant

    36  * nodes.

    37  *

    38  * @author Jonathan Gibbons

    39  * @since 1.6

    40  */

    41 public class TreePathScanner<R, P> extends TreeScanner<R, P> {

    43     /**

    44      * Scan a tree from a position identified by a TreePath.

    45      */

    46     public R scan(TreePath path, P p) {

    47         this.path = path;

    48         try {

    49             return path.getLeaf().accept(this, p);

    50         } finally {

    51             this.path = null;

    52         }

    53     }

    55     /**

    56      * Scan a single node.

    57      * The current path is updated for the duration of the scan.

    58      */

    59     @Override

    60     public R scan(Tree tree, P p) {

    61         if (tree == null)

    62             return null;

    64         TreePath prev = path;

    65         path = new TreePath(path, tree);

    66         try {

    67             return tree.accept(this, p);

    68         } finally {

    69             path = prev;

    70         }

    71     }

    73     /**

    74      * Get the current path for the node, as built up by the currently

    75      * active set of scan calls.

    76      */

    77     public TreePath getCurrentPath() {

    78         return path;

    79     }

    81     private TreePath path;

    82 }

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