ParseException


1   /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 2.1 */
2   package org.ejen.util.arl;
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   {
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  [] 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   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  [] 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   getMessage() {
96          if (!specialConstructor) {
97              return super.getMessage();
98          }
99          String   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   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   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   add_escapes(String   str) {
152         StringBuffer   retval = new StringBuffer  ();
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   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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