javacc-7.0.3.bin.templates.gwt.ParseException.template Maven / Gradle / Ivy
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JavaCC is a parser/scanner generator for Java.
/**
* 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 {
/**
* The version identifier for this Serializable class.
* Increment only if the serialized form of the
* class changes.
*/
private static final long serialVersionUID = 1L;
private static final String INDENT = " ";
/**
* The end of line string (we do not use System.getProperty("") so that we are compatible with Android/GWT);
*/
protected static String EOL = "\n";
public ParseException(Token currentTokenVal,
int[][] expectedTokenSequencesVal,
String[] tokenImageVal
)
{
this (currentTokenVal, expectedTokenSequencesVal, tokenImageVal, null);
}
/**
* 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.
*/
public ParseException(Token currentTokenVal,
int[][] expectedTokenSequencesVal,
String[] tokenImageVal,
String lexicalStateName
)
{
super(initialise(currentTokenVal, expectedTokenSequencesVal, tokenImageVal, lexicalStateName));
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();
}
/** Constructor with message. */
public ParseException(String message) {
super(message);
}
/**
* 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;
/**
* 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) the correct error message
* gets displayed.
*/
private static String initialise(Token currentToken,
int[][] expectedTokenSequences,
String[] tokenImage,
String lexicalStateName) {
StringBuilder sb = new StringBuilder();
StringBuffer expected = new StringBuffer();
int maxSize = 0;
java.util.TreeSet sortedOptions = new java.util.TreeSet();
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++) {
sortedOptions.add(tokenImage[expectedTokenSequences[i][j]]);
}
}
for (String option : sortedOptions) {
expected.append(INDENT).append(option).append(EOL);
}
sb.append("Encountered unexpected token:");
Token tok = currentToken.next;
for (int i = 0; i < maxSize; i++) {
String tokenText = tok.image;
String escapedTokenText = add_escapes(tokenText);
if (i != 0) {
sb.append(" ");
}
if (tok.kind == 0) {
sb.append(tokenImage[0]);
break;
}
sb.append(" \"");
sb.append(escapedTokenText);
sb.append("\"");
sb.append(" " + tokenImage[tok.kind]);
tok = tok.next;
}
#if KEEP_LINE_COLUMN
sb.append(EOL).append(INDENT).append("at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn);
#fi
sb.append(".").append(EOL);
if (expectedTokenSequences.length == 0) {
// Nothing to add here
} else {
int numExpectedTokens = expectedTokenSequences.length;
sb.append(EOL).append("Was expecting"+ (numExpectedTokens == 1 ? ":" : " one of:") + EOL + EOL);
sb.append(expected.toString());
}
// 2013/07/30 --> Seems to be inaccurate as represents the readahead state, not the lexical state BEFORE the unknown token
// if (lexicalStateName != null) {
// sb.append(EOL).append("** Lexical State : ").append(lexicalStateName).append(EOL).append(EOL);
// }
return sb.toString();
}
/**
* Used to convert raw characters to their escaped version
* when these raw version cannot be used as part of an ASCII
* string literal.
*/
static String add_escapes(String str) {
StringBuffer retval = new StringBuffer();
char ch;
for (int i = 0; i < str.length(); i++) {
switch (str.charAt(i))
{
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();
}
}