net.bonzoun.cocodonkey: public class: ParseException

net.bonzoun.cocodonkey
public class: ParseException [javadoc | source]

java.lang.Object
   java.lang.Throwable
      java.lang.Exception
         net.bonzoun.cocodonkey.ParseException

All Implemented Interfaces:
Serializable

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.

Field Summary
protected boolean	specialConstructor	This variable determines which constructor was used to create this object and thereby affects the semantics of the "getMessage" method (see below).
public Token	currentToken	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 int[][]	expectedTokenSequences	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 String[]	tokenImage	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.
protected String	eol	The end of line string for this machine.

Fields inherited from java.lang.Exception:
serialVersionUID

Constructor:
public ParseException() { super(); specialConstructor = false; } 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(String message) { super(message); specialConstructor = false; }
public ParseException(Token currentTokenVal, int[][] expectedTokenSequencesVal, String[] tokenImageVal) { super(""); specialConstructor = true; currentToken = currentTokenVal; expectedTokenSequences = expectedTokenSequencesVal; tokenImage = tokenImageVal; } 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:

Constructor:

 public ParseException() {
    super();
    specialConstructor = false;
}

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(String message) {
    super(message);
    specialConstructor = false;
}

 public ParseException(Token currentTokenVal,
    int[][] expectedTokenSequencesVal,
    String[] tokenImageVal) {
    super("");
    specialConstructor = true;
    currentToken = currentTokenVal;
    expectedTokenSequences = expectedTokenSequencesVal;
    tokenImage = tokenImageVal;
}

Method from net.bonzoun.cocodonkey.ParseException Summary:
add_escapes, getMessage

Methods from java.lang.Throwable:
addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getStackTraceDepth, getStackTraceElement, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from net.bonzoun.cocodonkey.ParseException Detail:
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(); } Used to convert raw characters to their escaped version when these raw version cannot be used as part of an ASCII string literal.
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 + "." + eol; if (expectedTokenSequences.length == 1) { retval += "Was expecting:" + eol + " "; } else { retval += "Was expecting one of:" + eol + " "; } retval += expected; return retval; } 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.

Method from net.bonzoun.cocodonkey.ParseException Detail:

 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();
}

Used to convert raw characters to their escaped version when these raw version cannot be used as part of an ASCII string literal.

 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 + "." + eol;
    if (expectedTokenSequences.length == 1) {
      retval += "Was expecting:" + eol + "    ";
    } else {
      retval += "Was expecting one of:" + eol + "    ";
    }
    retval += expected;
    return retval;
}

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.