001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2024 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 * <ul>
030 * <li>
031 * Property {@code format} - Sets the pattern to match valid identifiers.
032 * Type is {@code java.util.regex.Pattern}.
033 * Default value is {@code "^([a-z][a-zA-Z0-9]*|_)$"}.
034 * </li>
035 * </ul>
036 *
037 * <p>
038 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
039 * </p>
040 *
041 * <p>
042 * Violation Message Keys:
043 * </p>
044 * <ul>
045 * <li>
046 * {@code name.invalidPattern}
047 * </li>
048 * </ul>
049 *
050 * @since 8.36
051 */
052public class PatternVariableNameCheck extends AbstractNameCheck {
053
054    /** Creates a new {@code PatternVariableNameCheck} instance. */
055    public PatternVariableNameCheck() {
056        super("^([a-z][a-zA-Z0-9]*|_)$");
057    }
058
059    @Override
060    public int[] getDefaultTokens() {
061        return getRequiredTokens();
062    }
063
064    @Override
065    public int[] getAcceptableTokens() {
066        return getRequiredTokens();
067    }
068
069    @Override
070    public int[] getRequiredTokens() {
071        return new int[] {
072            TokenTypes.PATTERN_VARIABLE_DEF,
073        };
074    }
075
076    @Override
077    protected final boolean mustCheckName(DetailAST ast) {
078        return true;
079    }
080}