01: /*
02: * Licensed to the Apache Software Foundation (ASF) under one or more
03: * contributor license agreements. See the NOTICE file distributed with
04: * this work for additional information regarding copyright ownership.
05: * The ASF licenses this file to You under the Apache License, Version 2.0
06: * (the "License"); you may not use this file except in compliance with
07: * the License. You may obtain a copy of the License at
08: *
09: * http://www.apache.org/licenses/LICENSE-2.0
10: *
11: * Unless required by applicable law or agreed to in writing, software
12: * distributed under the License is distributed on an "AS IS" BASIS,
13: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14: * See the License for the specific language governing permissions and
15: * limitations under the License.
16: */
17: package org.apache.cocoon.components.xpointer.parser;
18:
19: /**
20: * Describes the input token stream.
21: */
22:
23: public class Token {
24:
25: /**
26: * An integer that describes the kind of this token. This numbering
27: * system is determined by JavaCCParser, and a table of these numbers is
28: * stored in the file ...Constants.java.
29: */
30: public int kind;
31:
32: /**
33: * beginLine and beginColumn describe the position of the first character
34: * of this token; endLine and endColumn describe the position of the
35: * last character of this token.
36: */
37: public int beginLine, beginColumn, endLine, endColumn;
38:
39: /**
40: * The string image of the token.
41: */
42: public String image;
43:
44: /**
45: * A reference to the next regular (non-special) token from the input
46: * stream. If this is the last token from the input stream, or if the
47: * token manager has not read tokens beyond this one, this field is
48: * set to null. This is true only if this token is also a regular
49: * token. Otherwise, see below for a description of the contents of
50: * this field.
51: */
52: public Token next;
53:
54: /**
55: * This field is used to access special tokens that occur prior to this
56: * token, but after the immediately preceding regular (non-special) token.
57: * If there are no such special tokens, this field is set to null.
58: * When there are more than one such special token, this field refers
59: * to the last of these special tokens, which in turn refers to the next
60: * previous special token through its specialToken field, and so on
61: * until the first special token (whose specialToken field is null).
62: * The next fields of special tokens refer to other special tokens that
63: * immediately follow it (without an intervening regular token). If there
64: * is no such token, this field is null.
65: */
66: public Token specialToken;
67:
68: /**
69: * Returns the image.
70: */
71: public String toString() {
72: return image;
73: }
74:
75: /**
76: * Returns a new Token object, by default. However, if you want, you
77: * can create and return subclass objects based on the value of ofKind.
78: * Simply add the cases to the switch for all those special cases.
79: * For example, if you have a subclass of Token called IDToken that
80: * you want to create if ofKind is ID, simlpy add something like :
81: *
82: * case MyParserConstants.ID : return new IDToken();
83: *
84: * to the following switch statement. Then you can cast matchedToken
85: * variable to the appropriate type and use it in your lexical actions.
86: */
87: public static final Token newToken(int ofKind) {
88: switch (ofKind) {
89: default:
90: return new Token();
91: }
92: }
93:
94: }
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