View Javadoc

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 {
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          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 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          StringBuffer expected = new StringBuffer();
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 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 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 add_escapes(String str) {
146         StringBuffer retval = new StringBuffer();
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 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 }