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Java > Open Source Codes > org > ejen > ext > parsers > java_1_2 > ParseException


1 /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 2.1 */
2 package org.ejen.ext.parsers.java_1_2;
3
4 /**
5  * This exception is thrown when parse errors are encountered.
6  * You can explicitly create objects of this exception type by
7  * calling the method generateParseException in the generated
8  * parser.
9  *
10  * You can modify this class to customize your error reporting
11  * mechanisms so long as you retain the public fields.
12  */

13 public class ParseException extends Exception JavaDoc {
14
15     /**
16      * This constructor is used by the method "generateParseException"
17      * in the generated parser. Calling this constructor generates
18      * a new object of this type with the fields "currentToken",
19      * "expectedTokenSequences", and "tokenImage" set. The boolean
20      * flag "specialConstructor" is also set to true to indicate that
21      * this constructor was used to create this object.
22      * This constructor calls its super class with the empty string
23      * to force the "toString" method of parent class "Throwable" to
24      * print the error message in the form:
25      * ParseException: <result of getMessage>
26      */

27     public ParseException(Token currentTokenVal,
28             int[][] expectedTokenSequencesVal,
29             String JavaDoc[] tokenImageVal
30             ) {
31         super("");
32         specialConstructor = true;
33         currentToken = currentTokenVal;
34         expectedTokenSequences = expectedTokenSequencesVal;
35         tokenImage = tokenImageVal;
36     }
37
38     /**
39      * The following constructors are for use by you for whatever
40      * purpose you can think of. Constructing the exception in this
41      * manner makes the exception behave in the normal way - i.e., as
42      * documented in the class "Throwable". The fields "errorToken",
43      * "expectedTokenSequences", and "tokenImage" do not contain
44      * relevant information. The JavaCC generated code does not use
45      * these constructors.
46      */

47     public ParseException() {
48         super();
49         specialConstructor = false;
50     }
51
52     public ParseException(String JavaDoc message) {
53         super(message);
54         specialConstructor = false;
55     }
56
57     /**
58      * This variable determines which constructor was used to create
59      * this object and thereby affects the semantics of the
60      * "getMessage" method (see below).
61      */

62     protected boolean specialConstructor;
63
64     /**
65      * This is the last token that has been consumed successfully. If
66      * this object has been created due to a parse error, the token
67      * followng this token will (therefore) be the first error token.
68      */

69     public Token currentToken;
70
71     /**
72      * Each entry in this array is an array of integers. Each array
73      * of integers represents a sequence of tokens (by their ordinal
74      * values) that is expected at this point of the parse.
75      */

76     public int[][] expectedTokenSequences;
77
78     /**
79      * This is a reference to the "tokenImage" array of the generated
80      * parser within which the parse error occurred. This array is
81      * defined in the generated ...Constants interface.
82      */

83     public String JavaDoc[] tokenImage;
84
85     /**
86      * This method has the standard behavior when this object has been
87      * created using the standard constructors. Otherwise, it uses
88      * "currentToken" and "expectedTokenSequences" to generate a parse
89      * error message and returns it. If this object has been created
90      * due to a parse error, and you do not catch it (it gets thrown
91      * from the parser), then this method is called during the printing
92      * of the final stack trace, and hence the correct error message
93      * gets displayed.
94      */

95     public String JavaDoc getMessage() {
96         if (!specialConstructor) {
97             return super.getMessage();
98         }
99         String JavaDoc expected = "";
100         int maxSize = 0;
101
102         for (int i = 0; i < expectedTokenSequences.length; i++) {
103             if (maxSize < expectedTokenSequences[i].length) {
104                 maxSize = expectedTokenSequences[i].length;
105             }
106             for (int j = 0; j < expectedTokenSequences[i].length; j++) {
107                 expected += tokenImage[expectedTokenSequences[i][j]] + " ";
108             }
109             if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1]
110                     != 0) {
111                 expected += "...";
112             }
113             expected += eol + " ";
114         }
115         String JavaDoc retval = "Encountered \"";
116         Token tok = currentToken.next;
117
118         for (int i = 0; i < maxSize; i++) {
119             if (i != 0) {
120                 retval += " ";
121             }
122             if (tok.kind == 0) {
123                 retval += tokenImage[0];
124                 break;
125             }
126             retval += add_escapes(tok.image);
127             tok = tok.next;
128         }
129         retval += "\" at line " + currentToken.next.beginLine + ", column "
130                 + currentToken.next.beginColumn;
131         retval += "." + eol;
132         if (expectedTokenSequences.length == 1) {
133             retval += "Was expecting:" + eol + " ";
134         } else {
135             retval += "Was expecting one of:" + eol + " ";
136         }
137         retval += expected;
138         return retval;
139     }
140
141     /**
142      * The end of line string for this machine.
143      */

144     protected String JavaDoc eol = System.getProperty("line.separator", "\n");
145  
146     /**
147      * Used to convert raw characters to their escaped version
148      * when these raw version cannot be used as part of an ASCII
149      * string literal.
150      */

151     protected String JavaDoc add_escapes(String JavaDoc str) {
152         StringBuffer JavaDoc retval = new StringBuffer JavaDoc();
153         char ch;
154
155         for (int i = 0; i < str.length(); i++) {
156             switch (str.charAt(i)) {
157             case 0:
158                 continue;
159
160             case '\b':
161                 retval.append("\\b");
162                 continue;
163
164             case '\t':
165                 retval.append("\\t");
166                 continue;
167
168             case '\n':
169                 retval.append("\\n");
170                 continue;
171
172             case '\f':
173                 retval.append("\\f");
174                 continue;
175
176             case '\r':
177                 retval.append("\\r");
178                 continue;
179
180             case '\"':
181                 retval.append("\\\"");
182                 continue;
183
184             case '\'':
185                 retval.append("\\\'");
186                 continue;
187
188             case '\\':
189                 retval.append("\\\\");
190                 continue;
191
192             default:
193                 if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
194                     String JavaDoc s = "0000" + Integer.toString(ch, 16);
195
196                     retval.append("\\u"
197                             + s.substring(s.length() - 4, s.length()));
198                 } else {
199                     retval.append(ch);
200                 }
201                 continue;
202             }
203         }
204         return retval.toString();
205     }
206 }
207
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