TokenMgrError.java

/*
* Copyright 2016 Nabarun Mondal
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/

package com.noga.njexl.lang.parser;

/**
 * Token Manager Error.
 */
public class TokenMgrError extends Error {
    /**
     * The version identifier for this Serializable class.
     * Increment only if the <i>serialized</i> 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.
     */
    private int errorCode;
    /**
     * The lexer state.
     */
    @SuppressWarnings("unused") // not read currently
    private int state;
    /**
     * The current character.
     */
    private char current;
    /**
     * Last correct input before error occurs.
     */
    private String after;
    /**
     * 
     */
    private boolean eof;
    /**
     * Error line.
     */
    private int line;
    /**
     * Error column.
     */
    private int column;
    
    /**
     * Gets the reason why the exception is thrown.
     * @return one of the 4 lexical error codes
     */
    public int getErrorCode() {
        return errorCode;
    }

    /**
     * Gets the line number.
     * @return line number.
     */
    public int getLine() {
        return line;
    }

    /**
     * Gets the column number.
     * @return the column.
     */
    public int getColumn() {
        return column;
    }
    
    /**
     * Gets the last correct input.
     * @return the string after which the error occured
     */
    public String getAfter() {
        return after;
    }
 

    /**
     * Returns a detailed message for the Error when it is thrown by the
     * token manager to indicate a lexical error.
     * @return the message
     */
    @Override
    public String getMessage() {
        return ("Lexical error at line "
                + line + ", column "
                + column + ".  Encountered: "
                + (eof ? "<EOF> "
                   : (StringParser.escapeString(String.valueOf(current), '"')) + " (" + (int) current + "), ")
                + "after : " + StringParser.escapeString(after, '"'));
    }


    /** 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) {
        eof = EOFSeen;
        state = lexState;
        line = errorLine;
        column = errorColumn;
        after = errorAfter;
        current = curChar;
        errorCode = reason;
    }
}