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 java.util.Objects; 023 024import com.puppycrawl.tools.checkstyle.api.DetailAST; 025import com.puppycrawl.tools.checkstyle.api.TokenTypes; 026import com.puppycrawl.tools.checkstyle.utils.TokenUtil; 027 028/** 029 * <p> 030 * Checks lambda parameter names. 031 * </p> 032 * <ul> 033 * <li> 034 * Property {@code format} - Sets the pattern to match valid identifiers. 035 * Type is {@code java.util.regex.Pattern}. 036 * Default value is {@code "^[a-z][a-zA-Z0-9]*$"}. 037 * </li> 038 * </ul> 039 * <p> 040 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 041 * </p> 042 * <p> 043 * Violation Message Keys: 044 * </p> 045 * <ul> 046 * <li> 047 * {@code name.invalidPattern} 048 * </li> 049 * </ul> 050 * 051 * @since 8.11 052 */ 053public class LambdaParameterNameCheck extends AbstractNameCheck { 054 055 /** Creates new instance of {@code LambdaParameterNameCheck}. */ 056 public LambdaParameterNameCheck() { 057 super("^[a-z][a-zA-Z0-9]*$"); 058 } 059 060 @Override 061 public int[] getDefaultTokens() { 062 return getRequiredTokens(); 063 } 064 065 @Override 066 public int[] getAcceptableTokens() { 067 return getRequiredTokens(); 068 } 069 070 @Override 071 public int[] getRequiredTokens() { 072 return new int[] { 073 TokenTypes.LAMBDA, 074 }; 075 } 076 077 @Override 078 public void visitToken(DetailAST ast) { 079 final boolean isInSwitchRule = ast.getParent().getType() == TokenTypes.SWITCH_RULE; 080 081 if (Objects.nonNull(ast.findFirstToken(TokenTypes.PARAMETERS))) { 082 final DetailAST parametersNode = ast.findFirstToken(TokenTypes.PARAMETERS); 083 TokenUtil.forEachChild(parametersNode, TokenTypes.PARAMETER_DEF, super::visitToken); 084 } 085 else if (!isInSwitchRule) { 086 super.visitToken(ast); 087 } 088 } 089 090 @Override 091 protected boolean mustCheckName(DetailAST ast) { 092 return true; 093 } 094 095}