io.questdb.griffin.engine.functions.regex.RegexUtils Maven / Gradle / Ivy

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 *  Copyright (c) 2014-2019 Appsicle
 *  Copyright (c) 2019-2023 QuestDB
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 *  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,
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package io.questdb.griffin.engine.functions.regex;

import io.questdb.cairo.sql.Function;
import io.questdb.griffin.SqlException;
import io.questdb.std.Chars;
import org.jetbrains.annotations.NotNull;

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;

final class RegexUtils {

    private RegexUtils() {
    }

    @NotNull
    public static Matcher createMatcher(Function pattern, int position) throws SqlException {
        final CharSequence regex = pattern.getStr(null);
        if (regex == null) {
            throw SqlException.$(position, "NULL regex");
        }
        try {
            return Pattern.compile(Chars.toString(regex)).matcher("");
        } catch (PatternSyntaxException e) {
            throw SqlException.$(position + e.getIndex() + 1, e.getMessage());
        }
    }
}