1
2 package net.sourceforge.pmd.ast;
3
4 /***
5 * Describes the input token stream.
6 */
7
8 public class Token {
9
10 /***
11 * An integer that describes the kind of this token. This numbering
12 * system is determined by JavaCCParser, and a table of these numbers is
13 * stored in the file ...Constants.java.
14 */
15 public int kind;
16
17 /***
18 * beginLine and beginColumn describe the position of the first character
19 * of this token; endLine and endColumn describe the position of the
20 * last character of this token.
21 */
22 public int beginLine, beginColumn, endLine, endColumn;
23
24 /***
25 * The string image of the token.
26 */
27 public String image;
28
29 /***
30 * A reference to the next regular (non-special) token from the input
31 * stream. If this is the last token from the input stream, or if the
32 * token manager has not read tokens beyond this one, this field is
33 * set to null. This is true only if this token is also a regular
34 * token. Otherwise, see below for a description of the contents of
35 * this field.
36 */
37 public Token next;
38
39 /***
40 * This field is used to access special tokens that occur prior to this
41 * token, but after the immediately preceding regular (non-special) token.
42 * If there are no such special tokens, this field is set to null.
43 * When there are more than one such special token, this field refers
44 * to the last of these special tokens, which in turn refers to the next
45 * previous special token through its specialToken field, and so on
46 * until the first special token (whose specialToken field is null).
47 * The next fields of special tokens refer to other special tokens that
48 * immediately follow it (without an intervening regular token). If there
49 * is no such token, this field is null.
50 */
51 public Token specialToken;
52
53 /***
54 * Returns the image.
55 */
56 public String toString() {
57 return image;
58 }
59
60 /***
61 * Returns a new Token object, by default. However, if you want, you
62 * can create and return subclass objects based on the value of ofKind.
63 * Simply add the cases to the switch for all those special cases.
64 * For example, if you have a subclass of Token called IDToken that
65 * you want to create if ofKind is ID, simlpy add something like :
66 * <p/>
67 * case MyParserConstants.ID : return new IDToken();
68 * <p/>
69 * to the following switch statement. Then you can cast matchedToken
70 * variable to the appropriate type and use it in your lexical actions.
71 */
72 public static final Token newToken(int ofKind) {
73 switch (ofKind) {
74 default :
75 return new Token();
76 case JavaParserConstants.RUNSIGNEDSHIFT:
77 case JavaParserConstants.RSIGNEDSHIFT:
78 case JavaParserConstants.GT:
79 return new GTToken();
80 }
81 }
82
83 public static class GTToken extends Token {
84 int realKind = JavaParserConstants.GT;
85 }
86
87
88 }