1
2 /***************************************************************************************
3 * Copyright (c) Jonas BonŽr, Alexandre Vasseur. All rights reserved. *
4 * http://aspectwerkz.codehaus.org *
5 * ---------------------------------------------------------------------------------- *
6 * The software in this package is published under the terms of the LGPL license *
7 * a copy of which has been included with this distribution in the license.txt file. *
8 **************************************************************************************/
9 package org.codehaus.aspectwerkz.expression.ast;
10
11 /***
12 * Describes the input token stream.
13 */
14
15 public class Token {
16
17 /***
18 * An integer that describes the kind of this token. This numbering system is determined by JavaCCParser, and a
19 * table of these numbers is stored in the file ...Constants.java.
20 */
21 public int kind;
22
23 /***
24 * beginLine and beginColumn describe the position of the first character of this token; endLine and endColumn
25 * describe the position of the last character of this token.
26 */
27 public int beginLine, beginColumn, endLine, endColumn;
28
29 /***
30 * The string image of the token.
31 */
32 public String image;
33
34 /***
35 * A reference to the next regular (non-special) token from the input stream. If this is the last token from the
36 * input stream, or if the token manager has not read tokens beyond this one, this field is set to null. This is
37 * true only if this token is also a regular token. Otherwise, see below for a description of the contents of this
38 * field.
39 */
40 public Token next;
41
42 /***
43 * This field is used to access special tokens that occur prior to this token, but after the immediately preceding
44 * regular (non-special) token. If there are no such special tokens, this field is set to null. When there are more
45 * than one such special token, this field refers to the last of these special tokens, which in turn refers to the
46 * next previous special token through its specialToken field, and so on until the first special token (whose
47 * specialToken field is null). The next fields of special tokens refer to other special tokens that immediately
48 * follow it (without an intervening regular token). If there is no such token, this field is null.
49 */
50 public Token specialToken;
51
52 /***
53 * Returns the image.
54 */
55 public String toString() {
56 return image;
57 }
58
59 /***
60 * Returns a new Token object, by default. However, if you want, you can create and return subclass objects based on
61 * the value of ofKind. Simply add the cases to the switch for all those special cases. For example, if you have a
62 * subclass of Token called IDToken that you want to create if ofKind is ID, simlpy add something like : case
63 * MyParserConstants.ID : return new IDToken(); to the following switch statement. Then you can cast matchedToken
64 * variable to the appropriate type and use it in your lexical actions.
65 */
66 public static final Token newToken(int ofKind) {
67 switch (ofKind) {
68 default:
69 return new Token();
70 }
71 }
72
73 }