/*
 * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
 *
 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
 * derivative works of, display, perform, and distribute the Software and make,
 * use, sell, offer for sale, import, export, have made, and have sold the
 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
 *
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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package com.oracle.truffle.regex.dead;

import com.oracle.truffle.regex.RegexExecRootNode;
import com.oracle.truffle.regex.RegexLanguage;
import com.oracle.truffle.regex.RegexSource;
import com.oracle.truffle.regex.result.NoMatchResult;
import com.oracle.truffle.regex.result.RegexResult;

This RegexNode is used for regular expressions that can never match, like /a^a/, /a\ba/, /(?=a)b/
etc.
/**
 * This RegexNode is used for regular expressions that can never match, like /a^a/, /a\ba/, /(?=a)b/
 * etc.
 */
public final class DeadRegexExecRootNode extends RegexExecRootNode {

    public DeadRegexExecRootNode(RegexLanguage language, RegexSource source) {
        super(language, source, false);
    }

    @Override
    protected RegexResult execute(Object input, int fromIndex) {
        return NoMatchResult.getInstance();
    }

    @Override
    protected String getEngineLabel() {
        return "dead";
    }
}