src/share/classes/com/sun/source/util/TreePathScanner.java

Wed, 27 Apr 2016 01:34:52 +0800

author
aoqi
date
Wed, 27 Apr 2016 01:34:52 +0800
changeset 0
959103a6100f
child 2525
2eb010b6cb22
permissions
-rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/langtools/
changeset: 2573:53ca196be1ae
tag: jdk8u25-b17

     1 /*
     2  * Copyright (c) 2006, 2013, Oracle and/or its affiliates. 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.  Oracle designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    22  * or visit www.oracle.com if you need additional information or have any
    23  * 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 @jdk.Exported
    42 public class TreePathScanner<R, P> extends TreeScanner<R, P> {
    44     /**
    45      * Scan a tree from a position identified by a TreePath.
    46      */
    47     public R scan(TreePath path, P p) {
    48         this.path = path;
    49         try {
    50             return path.getLeaf().accept(this, p);
    51         } finally {
    52             this.path = null;
    53         }
    54     }
    56     /**
    57      * Scan a single node.
    58      * The current path is updated for the duration of the scan.
    59      */
    60     @Override
    61     public R scan(Tree tree, P p) {
    62         if (tree == null)
    63             return null;
    65         TreePath prev = path;
    66         path = new TreePath(path, tree);
    67         try {
    68             return tree.accept(this, p);
    69         } finally {
    70             path = prev;
    71         }
    72     }
    74     /**
    75      * Get the current path for the node, as built up by the currently
    76      * active set of scan calls.
    77      */
    78     public TreePath getCurrentPath() {
    79         return path;
    80     }
    82     private TreePath path;
    83 }

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