Replaces unprintable characters by their espaced (or unicode escaped)
equivalents in the given string
protected static String LexicalError(boolean EOFSeen,
Returns a detailed message for the Error when it is thrown by the
token manager to indicate a lexical error.
EOFSeen : indicates if EOF caused the lexicl error
curLexState : lexical state in which this error occured
errorLine : line number when the error occured
errorColumn : column number when the error occured
errorAfter : prefix that was seen before this error occured
curchar : the offending character
Note: You can customize the lexical error message by modifying this method.
You can also modify the body of this method to customize your error messages.
For example, cases like LOOP_DETECTED and INVALID_LEXICAL_STATE are not
of end-users concern, so you can return something like :
"Internal Error : Please file a bug report .... "
from this method for such cases in the release version of your parser.