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Java > Open Source Codes > net > sourceforge > pmd > ast > ParseException


1 /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 3.0 */
2 package net.sourceforge.pmd.ast;
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  * <p/>
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 RuntimeException 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         super("");
31         specialConstructor = true;
32         currentToken = currentTokenVal;
33         expectedTokenSequences = expectedTokenSequencesVal;
34         tokenImage = tokenImageVal;
35     }
36
37     /**
38      * The following constructors are for use by you for whatever
39      * purpose you can think of. Constructing the exception in this
40      * manner makes the exception behave in the normal way - i.e., as
41      * documented in the class "Throwable". The fields "errorToken",
42      * "expectedTokenSequences", and "tokenImage" do not contain
43      * relevant information. The JavaCC generated code does not use
44      * these constructors.
45      */
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         StringBuffer JavaDoc expected = new StringBuffer JavaDoc();
100         int maxSize = 0;
101         for (int i = 0; i < expectedTokenSequences.length; i++) {
102             if (maxSize < expectedTokenSequences[i].length) {
103                 maxSize = expectedTokenSequences[i].length;
104             }
105             for (int j = 0; j < expectedTokenSequences[i].length; j++) {
106                 expected.append(tokenImage[expectedTokenSequences[i][j]]).append(' ');
107             }
108             if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
109                 expected.append("...");
110             }
111             expected.append(eol).append(" ");
112         }
113         String JavaDoc retval = "Encountered \"";
114         Token tok = currentToken.next;
115         for (int i = 0; i < maxSize; i++) {
116             if (i != 0) retval += " ";
117             if (tok.kind == 0) {
118                 retval += tokenImage[0];
119                 break;
120             }
121             retval += add_escapes(tok.image);
122             tok = tok.next;
123         }
124         retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
125         retval += "." + eol;
126         if (expectedTokenSequences.length == 1) {
127             retval += "Was expecting:" + eol + " ";
128         } else {
129             retval += "Was expecting one of:" + eol + " ";
130         }
131         retval += expected.toString();
132         return retval;
133     }
134
135     /**
136      * The end of line string for this machine.
137      */
138     protected String JavaDoc eol = System.getProperty("line.separator", "\n");
139
140     /**
141      * Used to convert raw characters to their escaped version
142      * when these raw version cannot be used as part of an ASCII
143      * string literal.
144      */
145     protected String JavaDoc add_escapes(String JavaDoc str) {
146         StringBuffer JavaDoc retval = new StringBuffer JavaDoc();
147         char ch;
148         for (int i = 0; i < str.length(); i++) {
149             switch (str.charAt(i)) {
150                 case 0:
151                     continue;
152                 case '\b':
153                     retval.append("\\b");
154                     continue;
155                 case '\t':
156                     retval.append("\\t");
157                     continue;
158                 case '\n':
159                     retval.append("\\n");
160                     continue;
161                 case '\f':
162                     retval.append("\\f");
163                     continue;
164                 case '\r':
165                     retval.append("\\r");
166                     continue;
167                 case '\"':
168                     retval.append("\\\"");
169                     continue;
170                 case '\'':
171                     retval.append("\\\'");
172                     continue;
173                 case '\\':
174                     retval.append("\\\\");
175                     continue;
176                 default:
177                     if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
178                         String JavaDoc s = "0000" + Integer.toString(ch, 16);
179                         retval.append("\\u" + s.substring(s.length() - 4, s.length()));
180                     } else {
181                         retval.append(ch);
182                     }
183                     continue;
184             }
185         }
186         return retval.toString();
187     }
188
189 }
190
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