KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > de > gulden > util > javasource > jjt > ParseException


1 /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 3.0 */
2 package de.gulden.util.javasource.jjt;
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   {
32     super("");
33     specialConstructor = true;
34     currentToken = currentTokenVal;
35     expectedTokenSequences = expectedTokenSequencesVal;
36     tokenImage = tokenImageVal;
37   }
38
39   /**
40    * The following constructors are for use by you for whatever
41    * purpose you can think of. Constructing the exception in this
42    * manner makes the exception behave in the normal way - i.e., as
43    * documented in the class "Throwable". The fields "errorToken",
44    * "expectedTokenSequences", and "tokenImage" do not contain
45    * relevant information. The JavaCC generated code does not use
46    * these constructors.
47    */
48
49   public ParseException() {
50     super();
51     specialConstructor = false;
52   }
53
54   public ParseException(String JavaDoc message) {
55     super(message);
56     specialConstructor = false;
57   }
58
59   /**
60    * This variable determines which constructor was used to create
61    * this object and thereby affects the semantics of the
62    * "getMessage" method (see below).
63    */
64   protected boolean specialConstructor;
65
66   /**
67    * This is the last token that has been consumed successfully. If
68    * this object has been created due to a parse error, the token
69    * followng this token will (therefore) be the first error token.
70    */
71   public Token currentToken;
72
73   /**
74    * Each entry in this array is an array of integers. Each array
75    * of integers represents a sequence of tokens (by their ordinal
76    * values) that is expected at this point of the parse.
77    */
78   public int[][] expectedTokenSequences;
79
80   /**
81    * This is a reference to the "tokenImage" array of the generated
82    * parser within which the parse error occurred. This array is
83    * defined in the generated ...Constants interface.
84    */
85   public String JavaDoc[] tokenImage;
86
87   /**
88    * This method has the standard behavior when this object has been
89    * created using the standard constructors. Otherwise, it uses
90    * "currentToken" and "expectedTokenSequences" to generate a parse
91    * error message and returns it. If this object has been created
92    * due to a parse error, and you do not catch it (it gets thrown
93    * from the parser), then this method is called during the printing
94    * of the final stack trace, and hence the correct error message
95    * gets displayed.
96    */
97   public String JavaDoc getMessage() {
98     if (!specialConstructor) {
99       return super.getMessage();
100     }
101     String JavaDoc expected = "";
102     int maxSize = 0;
103     for (int i = 0; i < expectedTokenSequences.length; i++) {
104       if (maxSize < expectedTokenSequences[i].length) {
105         maxSize = expectedTokenSequences[i].length;
106       }
107       for (int j = 0; j < expectedTokenSequences[i].length; j++) {
108         expected += tokenImage[expectedTokenSequences[i][j]] + " ";
109       }
110       if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
111         expected += "...";
112       }
113       expected += eol + " ";
114     }
115     String JavaDoc retval = "Encountered \"";
116     Token tok = currentToken.next;
117     for (int i = 0; i < maxSize; i++) {
118       if (i != 0) retval += " ";
119       if (tok.kind == 0) {
120         retval += tokenImage[0];
121         break;
122       }
123       retval += add_escapes(tok.image);
124       tok = tok.next;
125     }
126     retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
127     retval += "." + eol;
128     if (expectedTokenSequences.length == 1) {
129       retval += "Was expecting:" + eol + " ";
130     } else {
131       retval += "Was expecting one of:" + eol + " ";
132     }
133     retval += expected;
134     return retval;
135   }
136
137   /**
138    * The end of line string for this machine.
139    */
140   protected String JavaDoc eol = System.getProperty("line.separator", "\n");
141  
142   /**
143    * Used to convert raw characters to their escaped version
144    * when these raw version cannot be used as part of an ASCII
145    * string literal.
146    */
147   protected String JavaDoc add_escapes(String JavaDoc str) {
148       StringBuffer JavaDoc retval = new StringBuffer JavaDoc();
149       char ch;
150       for (int i = 0; i < str.length(); i++) {
151         switch (str.charAt(i))
152         {
153            case 0 :
154               continue;
155            case '\b':
156               retval.append("\\b");
157               continue;
158            case '\t':
159               retval.append("\\t");
160               continue;
161            case '\n':
162               retval.append("\\n");
163               continue;
164            case '\f':
165               retval.append("\\f");
166               continue;
167            case '\r':
168               retval.append("\\r");
169               continue;
170            case '\"':
171               retval.append("\\\"");
172               continue;
173            case '\'':
174               retval.append("\\\'");
175               continue;
176            case '\\':
177               retval.append("\\\\");
178               continue;
179            default:
180               if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
181                  String JavaDoc s = "0000" + Integer.toString(ch, 16);
182                  retval.append("\\u" + s.substring(s.length() - 4, s.length()));
183               } else {
184                  retval.append(ch);
185               }
186               continue;
187         }
188       }
189       return retval.toString();
190    }
191
192 }
193
Popular Tags