org.antlr.v4.runtime.FailedPredicateException.java Source code

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Here is the source code for org.antlr.v4.runtime.FailedPredicateException.java

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/*
 * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */
package org.antlr.v4.runtime;

import org.antlr.v4.runtime.atn.ATNState;
import org.antlr.v4.runtime.atn.AbstractPredicateTransition;
import org.antlr.v4.runtime.atn.PredicateTransition;

import java.util.Locale;

/** A semantic predicate failed during validation.  Validation of predicates
 *  occurs when normally parsing the alternative just like matching a token.
 *  Disambiguating predicate evaluation occurs when we test a predicate during
 *  prediction.
 */
public class FailedPredicateException extends RecognitionException {
    private final int ruleIndex;
    private final int predicateIndex;
    private final String predicate;

    public FailedPredicateException(Parser recognizer) {
        this(recognizer, null);
    }

    public FailedPredicateException(Parser recognizer, String predicate) {
        this(recognizer, predicate, null);
    }

    public FailedPredicateException(Parser recognizer, String predicate, String message) {
        super(formatMessage(predicate, message), recognizer, recognizer.getInputStream(), recognizer._ctx);
        ATNState s = recognizer.getInterpreter().atn.states.get(recognizer.getState());

        AbstractPredicateTransition trans = (AbstractPredicateTransition) s.transition(0);
        if (trans instanceof PredicateTransition) {
            this.ruleIndex = ((PredicateTransition) trans).ruleIndex;
            this.predicateIndex = ((PredicateTransition) trans).predIndex;
        } else {
            this.ruleIndex = 0;
            this.predicateIndex = 0;
        }

        this.predicate = predicate;
        this.setOffendingToken(recognizer.getCurrentToken());
    }

    public int getRuleIndex() {
        return ruleIndex;
    }

    public int getPredIndex() {
        return predicateIndex;
    }

    public String getPredicate() {
        return predicate;
    }

    private static String formatMessage(String predicate, String message) {
        if (message != null) {
            return message;
        }

        return String.format(Locale.getDefault(), "failed predicate: {%s}?", predicate);
    }
}