001: /* Generated By:JavaCC: Do not edit this line. ParseException.java Version 3.0 */
002: package xtc.lang.javacc;
003:
004: /**
005: * This exception is thrown when parse errors are encountered.
006: * You can explicitly create objects of this exception type by
007: * calling the method generateParseException in the generated
008: * parser.
009: *
010: * You can modify this class to customize your error reporting
011: * mechanisms so long as you retain the public fields.
012: */
013: public class ParseException extends Exception {
014:
015: /**
016: * This constructor is used by the method "generateParseException"
017: * in the generated parser. Calling this constructor generates
018: * a new object of this type with the fields "currentToken",
019: * "expectedTokenSequences", and "tokenImage" set. The boolean
020: * flag "specialConstructor" is also set to true to indicate that
021: * this constructor was used to create this object.
022: * This constructor calls its super class with the empty string
023: * to force the "toString" method of parent class "Throwable" to
024: * print the error message in the form:
025: * ParseException: <result of getMessage>
026: */
027: public ParseException(Token currentTokenVal,
028: int[][] expectedTokenSequencesVal, String[] tokenImageVal) {
029: super ("");
030: specialConstructor = true;
031: currentToken = currentTokenVal;
032: expectedTokenSequences = expectedTokenSequencesVal;
033: tokenImage = tokenImageVal;
034: }
035:
036: /**
037: * The following constructors are for use by you for whatever
038: * purpose you can think of. Constructing the exception in this
039: * manner makes the exception behave in the normal way - i.e., as
040: * documented in the class "Throwable". The fields "errorToken",
041: * "expectedTokenSequences", and "tokenImage" do not contain
042: * relevant information. The JavaCC generated code does not use
043: * these constructors.
044: */
045:
046: public ParseException() {
047: super ();
048: specialConstructor = false;
049: }
050:
051: public ParseException(String message) {
052: super (message);
053: specialConstructor = false;
054: }
055:
056: /**
057: * This variable determines which constructor was used to create
058: * this object and thereby affects the semantics of the
059: * "getMessage" method (see below).
060: */
061: protected boolean specialConstructor;
062:
063: /**
064: * This is the last token that has been consumed successfully. If
065: * this object has been created due to a parse error, the token
066: * followng this token will (therefore) be the first error token.
067: */
068: public Token currentToken;
069:
070: /**
071: * Each entry in this array is an array of integers. Each array
072: * of integers represents a sequence of tokens (by their ordinal
073: * values) that is expected at this point of the parse.
074: */
075: public int[][] expectedTokenSequences;
076:
077: /**
078: * This is a reference to the "tokenImage" array of the generated
079: * parser within which the parse error occurred. This array is
080: * defined in the generated ...Constants interface.
081: */
082: public String[] tokenImage;
083:
084: /**
085: * This method has the standard behavior when this object has been
086: * created using the standard constructors. Otherwise, it uses
087: * "currentToken" and "expectedTokenSequences" to generate a parse
088: * error message and returns it. If this object has been created
089: * due to a parse error, and you do not catch it (it gets thrown
090: * from the parser), then this method is called during the printing
091: * of the final stack trace, and hence the correct error message
092: * gets displayed.
093: */
094: public String getMessage() {
095: if (!specialConstructor) {
096: return super .getMessage();
097: }
098: String expected = "";
099: int maxSize = 0;
100: for (int i = 0; i < expectedTokenSequences.length; i++) {
101: if (maxSize < expectedTokenSequences[i].length) {
102: maxSize = expectedTokenSequences[i].length;
103: }
104: for (int j = 0; j < expectedTokenSequences[i].length; j++) {
105: expected += tokenImage[expectedTokenSequences[i][j]]
106: + " ";
107: }
108: if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
109: expected += "...";
110: }
111: expected += eol + " ";
112: }
113: String retval = "Encountered \"";
114: Token tok = currentToken.next;
115: for (int i = 0; i < maxSize; i++) {
116: if (i != 0)
117: retval += " ";
118: if (tok.kind == 0) {
119: retval += tokenImage[0];
120: break;
121: }
122: retval += add_escapes(tok.image);
123: tok = tok.next;
124: }
125: retval += "\" at line " + currentToken.next.beginLine
126: + ", 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 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 add_escapes(String str) {
148: StringBuffer retval = new StringBuffer();
149: char ch;
150: for (int i = 0; i < str.length(); i++) {
151: switch (str.charAt(i)) {
152: case 0:
153: continue;
154: case '\b':
155: retval.append("\\b");
156: continue;
157: case '\t':
158: retval.append("\\t");
159: continue;
160: case '\n':
161: retval.append("\\n");
162: continue;
163: case '\f':
164: retval.append("\\f");
165: continue;
166: case '\r':
167: retval.append("\\r");
168: continue;
169: case '\"':
170: retval.append("\\\"");
171: continue;
172: case '\'':
173: retval.append("\\\'");
174: continue;
175: case '\\':
176: retval.append("\\\\");
177: continue;
178: default:
179: if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
180: String s = "0000" + Integer.toString(ch, 16);
181: retval.append("\\u"
182: + 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: }
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