ParseException


1   /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 0.7pre6 */
2   package org.python.parser;
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    {
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   message) {
55      super(message);
56      specialConstructor = false;
57    }
58  
59    public ParseException(String   message, SimpleNode node) {
60      super(message);
61      // If a node is passed in, provide just enough info to get current line/column out
62      Token t = new Token();
63      t.beginLine = node.beginLine;
64      t.beginColumn = node.beginColumn;
65      
66      currentToken = new Token();
67      currentToken.next = t;
68      t = currentToken;
69      t.beginLine = node.beginLine;
70      t.beginColumn = node.beginColumn;
71      
72      specialConstructor = false;
73    }
74  
75    /**
76     * This variable determines which constructor was used to create
77     * this object and thereby affects the semantics of the
78     * "getMessage" method (see below).
79     */
80    protected boolean specialConstructor;
81  
82    /**
83     * This is the last token that has been consumed successfully.  If
84     * this object has been created due to a parse error, the token
85     * followng this token will (therefore) be the first error token.
86     */
87    public Token currentToken;
88  
89    /**
90     * Each entry in this array is an array of integers.  Each array
91     * of integers represents a sequence of tokens (by their ordinal
92     * values) that is expected at this point of the parse.
93     */
94    public int[][] expectedTokenSequences;
95  
96    /**
97     * This is a reference to the "tokenImage" array of the generated
98     * parser within which the parse error occurred.  This array is
99     * defined in the generated ...Constants interface.
100    */
101   public String  [] tokenImage;
102 
103   /**
104    * This method has the standard behavior when this object has been
105    * created using the standard constructors.  Otherwise, it uses
106    * "currentToken" and "expectedTokenSequences" to generate a parse
107    * error message and returns it.  If this object has been created
108    * due to a parse error, and you do not catch it (it gets thrown
109    * from the parser), then this method is called during the printing
110    * of the final stack trace, and hence the correct error message
111    * gets displayed.
112    */
113    public static boolean verboseExceptions = false;
114   public String   getMessage() {
115     if (!specialConstructor) {
116       return super.getMessage();
117     }
118     if (verboseExceptions) {
119         String   expected = "";
120         int maxSize = 0;
121         for (int i = 0; i < expectedTokenSequences.length; i++) {
122           if (maxSize < expectedTokenSequences[i].length) {
123             maxSize = expectedTokenSequences[i].length;
124           }
125           for (int j = 0; j < expectedTokenSequences[i].length; j++) {
126             expected += tokenImage[expectedTokenSequences[i][j]] + " ";
127           }
128           if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
129             expected += "...";
130           }
131           expected += eol + "    ";
132         }
133         String   retval = "Encountered \"";
134         Token tok = currentToken.next;
135         for (int i = 0; i < maxSize; i++) {
136           if (i != 0) retval += " ";
137           if (tok.kind == 0) {
138             retval += tokenImage[0];
139             break;
140           }
141           retval += add_escapes(tok.image);
142           tok = tok.next; 
143         }
144         retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn + "." + eol;
145         if (expectedTokenSequences.length == 1) {
146           retval += "Was expecting:" + eol + "    ";
147         } else {
148           retval += "Was expecting one of:" + eol + "    ";
149         }
150         retval += expected;
151         return retval;
152     } else {
153         return "invalid syntax";
154     }
155   }
156 
157   /**
158    * The end of line string for this machine.
159    */
160   protected String   eol = System.getProperty("line.separator", "\n");
161  
162   /**
163    * Used to convert raw characters to their escaped version
164    * when these raw version cannot be used as part of an ASCII
165    * string literal.
166    */
167   protected String   add_escapes(String   str) {
168       StringBuffer   retval = new StringBuffer  ();
169       char ch;
170       for (int i = 0; i < str.length(); i++) {
171         switch (str.charAt(i))
172         {
173            case 0 :
174               continue;
175            case '\b':
176               retval.append("\\b");
177               continue;
178            case '\t':
179               retval.append("\\t");
180               continue;
181            case '\n':
182               retval.append("\\n");
183               continue;
184            case '\f':
185               retval.append("\\f");
186               continue;
187            case '\r':
188               retval.append("\\r");
189               continue;
190            case '\"':
191               retval.append("\\\"");
192               continue;
193            case '\'':
194               retval.append("\\\'");
195               continue;
196            case '\\':
197               retval.append("\\\\");
198               continue;
199            default:
200               if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
201                  String   s = "0000" + Integer.toString(ch, 16);
202                  retval.append("\\u" + s.substring(s.length() - 4, s.length()));
203               } else {
204                  retval.append(ch);
205               }
206               continue;
207         }
208       }
209       return retval.toString();
210    }
211 
212 }
213
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