org.graphstream.util.parser.TokenMgrError Maven / Gradle / Ivy

/*
 * This file is part of GraphStream .
 * 
 * GraphStream is a library whose purpose is to handle static or dynamic
 * graph, create them from scratch, file or any source and display them.
 * 
 * This program is free software distributed under the terms of two licenses, the
 * CeCILL-C license that fits European law, and the GNU Lesser General Public
 * License. You can  use, modify and/ or redistribute the software under the terms
 * of the CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
 * URL  or under the terms of the GNU LGPL as published by
 * the Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see .
 * 
 * The fact that you are presently reading this means that you have had
 * knowledge of the CeCILL-C and LGPL licenses and that you accept their terms.
 */

/**
 * @since 2009-02-19
 * 
 * @author Guilhelm Savin 
 * @author Hicham Brahimi 
 */
package org.graphstream.util.parser;

/** Token Manager Error. */
public class TokenMgrError extends Error {

	/**
	 * The version identifier for this Serializable class. Increment only if the
	 * serialized form of the class changes.
	 */
	private static final long serialVersionUID = 1L;

	/*
	 * Ordinals for various reasons why an Error of this type can be thrown.
	 */

	/**
	 * Lexical error occurred.
	 */
	public static final int LEXICAL_ERROR = 0;

	/**
	 * An attempt was made to create a second instance of a static token manager.
	 */
	public static final int STATIC_LEXER_ERROR = 1;

	/**
	 * Tried to change to an invalid lexical state.
	 */
	public static final int INVALID_LEXICAL_STATE = 2;

	/**
	 * Detected (and bailed out of) an infinite loop in the token manager.
	 */
	public static final int LOOP_DETECTED = 3;

	/**
	 * Indicates the reason why the exception is thrown. It will have one of the
	 * above 4 values.
	 */
	int errorCode;

	/**
	 * Replaces unprintable characters by their escaped (or unicode escaped)
	 * equivalents in the given string
	 */
	protected static final String addEscapes(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();
	}

	/**
	 * Returns a detailed message for the Error when it is thrown by the token
	 * manager to indicate a lexical error. Parameters : EOFSeen : indicates if EOF
	 * caused the lexical error curLexState : lexical state in which this error
	 * occurred errorLine : line number when the error occurred errorColumn : column
	 * number when the error occurred errorAfter : prefix that was seen before this
	 * error occurred curchar : the offending character Note: You can customize the
	 * lexical error message by modifying this method.
	 */
	protected static String LexicalError(boolean EOFSeen, int lexState, int errorLine, int errorColumn,
			String errorAfter, char curChar) {
		return ("Lexical error at line " + errorLine + ", column " + errorColumn + ".  Encountered: "
				+ (EOFSeen ? " "
						: ("\"" + addEscapes(String.valueOf(curChar)) + "\"") + " (" + (int) curChar + "), ")
				+ "after : \"" + addEscapes(errorAfter) + "\"");
	}

	/**
	 * 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.
	 */
	public String getMessage() {
		return super.getMessage();
	}

	/*
	 * Constructors of various flavors follow.
	 */

	/** No arg constructor. */
	public TokenMgrError() {
	}

	/** Constructor with message and reason. */
	public TokenMgrError(String message, int reason) {
		super(message);
		errorCode = reason;
	}

	/** Full Constructor. */
	public TokenMgrError(boolean EOFSeen, int lexState, int errorLine, int errorColumn, String errorAfter, char curChar,
			int reason) {
		this(LexicalError(EOFSeen, lexState, errorLine, errorColumn, errorAfter, curChar), reason);
	}
}