001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.naming;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024
025/**
026 * <div>
027 * Checks that pattern variable names conform to a specified pattern.
028 * </div>
029 *
030 * @since 8.36
031 */
032public class PatternVariableNameCheck extends AbstractNameCheck {
033
034    /**
035     * A key is pointing to the warning message text in "messages.properties" file.
036     */
037    public static final String MSG_INVALID_PATTERN = "name.invalidPattern";
038
039    /** Creates a new {@code PatternVariableNameCheck} instance. */
040    public PatternVariableNameCheck() {
041        super("^([a-z][a-zA-Z0-9]*|_)$", MSG_INVALID_PATTERN);
042    }
043
044    @Override
045    public int[] getDefaultTokens() {
046        return getRequiredTokens();
047    }
048
049    @Override
050    public int[] getAcceptableTokens() {
051        return getRequiredTokens();
052    }
053
054    @Override
055    public int[] getRequiredTokens() {
056        return new int[] {
057            TokenTypes.PATTERN_VARIABLE_DEF,
058        };
059    }
060
061    @Override
062    protected final boolean mustCheckName(DetailAST ast) {
063        return true;
064    }
065
066}