com.jmcalc.utils.DescriptiveErrorListener.java Source code

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Here is the source code for com.jmcalc.utils.DescriptiveErrorListener.java

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/*
 *  Copyright 2012-2013 Marcelo Portilho
 *
 *  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.jmcalc.utils;

import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.CommonToken;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.misc.Interval;

import com.jmcalc.exceptions.ExpressionParseException;

public class DescriptiveErrorListener extends BaseErrorListener {

    public static DescriptiveErrorListener INSTANCE = new DescriptiveErrorListener();

    @Override
    public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line, int charPositionInLine,
            String msg, RecognitionException e) {
        CommonToken offendingToken = ((CommonToken) offendingSymbol);
        String sourceName = offendingToken.getInputStream()
                .getText(new Interval(0, offendingToken.getInputStream().size()));
        if (e != null) {
            throw new ExpressionParseException(sourceName + " -> line " + line + ":" + charPositionInLine
                    + " mismatched input '" + e.getOffendingToken().getText() + "'");
        } else {
            throw new ExpressionParseException(sourceName + " -> line " + line + ":" + charPositionInLine
                    + " unexpected token: " + offendingToken.getText());
        }
    }

}