UnknownTreeException.java revision 1590:1916a2c680d8 
1/*
2 * Copyright (c) 2015, 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 */
25
26package jdk.nashorn.api.tree;
27
28
29/**
30 * Indicates that an unknown kind of Tree was encountered.  This
31 * can occur if the language evolves and new kinds of Trees are
32 * added to the {@code Tree} hierarchy.  May be thrown by a
33 * {@linkplain TreeVisitor tree visitor} to indicate that the
34 * visitor was created for a prior version of the language.
35 *
36 * @since 1.9
37 */
38public class UnknownTreeException extends RuntimeException {
39
40    private static final long serialVersionUID = 1L;
41
42    private transient final Tree tree;
43    private transient final Object parameter;
44
45    /**
46     * Creates a new {@code UnknownTreeException}.  The {@code p}
47     * parameter may be used to pass in an additional argument with
48     * information about the context in which the unknown element was
49     * encountered; for example, the visit methods of {@link
50     * TreeVisitor} may pass in their additional parameter.
51     *
52     * @param t the unknown tree, may be {@code null}
53     * @param p an additional parameter, may be {@code null}
54     */
55    public UnknownTreeException(Tree t, Object p) {
56        super("Unknown tree: " + t);
57        this.tree = t;
58        this.parameter = p;
59    }
60
61    /**
62     * Returns the unknown tree.
63     * The value may be unavailable if this exception has been
64     * serialized and then read back in.
65     *
66     * @return the unknown element, or {@code null} if unavailable
67     */
68    public Tree getUnknownTree() {
69        return tree;
70    }
71
72    /**
73     * Returns the additional argument.
74     * The value may be unavailable if this exception has been
75     * serialized and then read back in.
76     *
77     * @return the additional argument
78     */
79    public Object getArgument() {
80        return parameter;
81    }
82}
83