/******************************************************************************* | |
* Copyright (c) 2004-2008 Andras Balogh and Daniel Varro | |
* All rights reserved. This program and the accompanying materials | |
* are made available under the terms of the Eclipse Public License v1.0 | |
* which accompanies this distribution, and is available at | |
* http://www.eclipse.org/legal/epl-v10.html | |
* | |
* Contributors: | |
* Andras Balogh - initial API and implementation | |
*******************************************************************************/ | |
package org.eclipse.viatra2.imports.vtml; | |
/** | |
* This exception is thrown when parse errors are encountered. | |
* You can explicitly create objects of this exception type by | |
* calling the method generateParseException in the generated | |
* parser. | |
* | |
* You can modify this class to customize your error reporting | |
* mechanisms so long as you retain the public fields. | |
*/ | |
public class ParseException extends Exception { | |
/** | |
* This constructor is used by the method "generateParseException" | |
* in the generated parser. Calling this constructor generates | |
* a new object of this type with the fields "currentToken", | |
* "expectedTokenSequences", and "tokenImage" set. The boolean | |
* flag "specialConstructor" is also set to true to indicate that | |
* this constructor was used to create this object. | |
* This constructor calls its super class with the empty string | |
* to force the "toString" method of parent class "Throwable" to | |
* print the error message in the form: | |
* ParseException: <result of getMessage> | |
*/ | |
public ParseException(Token currentTokenVal, | |
int[][] expectedTokenSequencesVal, | |
String[] tokenImageVal | |
) | |
{ | |
super(""); | |
specialConstructor = true; | |
currentToken = currentTokenVal; | |
expectedTokenSequences = expectedTokenSequencesVal; | |
tokenImage = tokenImageVal; | |
} | |
/** | |
* The following constructors are for use by you for whatever | |
* purpose you can think of. Constructing the exception in this | |
* manner makes the exception behave in the normal way - i.e., as | |
* documented in the class "Throwable". The fields "errorToken", | |
* "expectedTokenSequences", and "tokenImage" do not contain | |
* relevant information. The JavaCC generated code does not use | |
* these constructors. | |
*/ | |
public ParseException() { | |
super(); | |
specialConstructor = false; | |
} | |
public ParseException(String message) { | |
super(message); | |
specialConstructor = false; | |
} | |
/** | |
* This variable determines which constructor was used to create | |
* this object and thereby affects the semantics of the | |
* "getMessage" method (see below). | |
*/ | |
protected boolean specialConstructor; | |
/** | |
* This is the last token that has been consumed successfully. If | |
* this object has been created due to a parse error, the token | |
* followng this token will (therefore) be the first error token. | |
*/ | |
public Token currentToken; | |
/** | |
* Each entry in this array is an array of integers. Each array | |
* of integers represents a sequence of tokens (by their ordinal | |
* values) that is expected at this point of the parse. | |
*/ | |
public int[][] expectedTokenSequences; | |
/** | |
* This is a reference to the "tokenImage" array of the generated | |
* parser within which the parse error occurred. This array is | |
* defined in the generated ...Constants interface. | |
*/ | |
public String[] tokenImage; | |
/** | |
* This method has the standard behavior when this object has been | |
* created using the standard constructors. Otherwise, it uses | |
* "currentToken" and "expectedTokenSequences" to generate a parse | |
* error message and returns it. If this object has been created | |
* due to a parse error, and you do not catch it (it gets thrown | |
* from the parser), then this method is called during the printing | |
* of the final stack trace, and hence the correct error message | |
* gets displayed. | |
*/ | |
public String getMessage() { | |
if (!specialConstructor) { | |
return super.getMessage(); | |
} | |
String expected = ""; | |
int maxSize = 0; | |
for (int i = 0; i < expectedTokenSequences.length; i++) { | |
if (maxSize < expectedTokenSequences[i].length) { | |
maxSize = expectedTokenSequences[i].length; | |
} | |
for (int j = 0; j < expectedTokenSequences[i].length; j++) { | |
expected += tokenImage[expectedTokenSequences[i][j]] + " "; | |
} | |
if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) { | |
expected += "..."; | |
} | |
expected += eol + " "; | |
} | |
String retval = "Encountered \""; | |
Token tok = currentToken.next; | |
for (int i = 0; i < maxSize; i++) { | |
if (i != 0) retval += " "; | |
if (tok.kind == 0) { | |
retval += tokenImage[0]; | |
break; | |
} | |
retval += add_escapes(tok.image); | |
tok = tok.next; | |
} | |
retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn; | |
retval += "." + eol; | |
if (expectedTokenSequences.length == 1) { | |
retval += "Was expecting:" + eol + " "; | |
} else { | |
retval += "Was expecting one of:" + eol + " "; | |
} | |
retval += expected; | |
return retval; | |
} | |
/** | |
* The end of line string for this machine. | |
*/ | |
protected String eol = System.getProperty("line.separator", "\n"); | |
/** | |
* Used to convert raw characters to their escaped version | |
* when these raw version cannot be used as part of an ASCII | |
* string literal. | |
*/ | |
protected String add_escapes(String str) { | |
StringBuffer retval = new StringBuffer(); | |
char ch; | |
for (int i = 0; i < str.length(); i++) { | |
switch (str.charAt(i)) | |
{ | |
case 0 : | |
continue; | |
case '\b': | |
retval.append("\\b"); | |
continue; | |
case '\t': | |
retval.append("\\t"); | |
continue; | |
case '\n': | |
retval.append("\\n"); | |
continue; | |
case '\f': | |
retval.append("\\f"); | |
continue; | |
case '\r': | |
retval.append("\\r"); | |
continue; | |
case '\"': | |
retval.append("\\\""); | |
continue; | |
case '\'': | |
retval.append("\\\'"); | |
continue; | |
case '\\': | |
retval.append("\\\\"); | |
continue; | |
default: | |
if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) { | |
String s = "0000" + Integer.toString(ch, 16); | |
retval.append("\\u" + s.substring(s.length() - 4, s.length())); | |
} else { | |
retval.append(ch); | |
} | |
continue; | |
} | |
} | |
return retval.toString(); | |
} | |
} |