1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2025 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks.naming;
21
22 import java.util.Objects;
23
24 import com.puppycrawl.tools.checkstyle.api.DetailAST;
25 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
26 import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
27
28 /**
29 * <div>
30 * Checks lambda parameter names.
31 * </div>
32 *
33 * @since 8.11
34 */
35 public class LambdaParameterNameCheck extends AbstractNameCheck {
36
37 /** Creates new instance of {@code LambdaParameterNameCheck}. */
38 public LambdaParameterNameCheck() {
39 super("^([a-z][a-zA-Z0-9]*|_)$");
40 }
41
42 @Override
43 public int[] getDefaultTokens() {
44 return getRequiredTokens();
45 }
46
47 @Override
48 public int[] getAcceptableTokens() {
49 return getRequiredTokens();
50 }
51
52 @Override
53 public int[] getRequiredTokens() {
54 return new int[] {
55 TokenTypes.LAMBDA,
56 };
57 }
58
59 @Override
60 public void visitToken(DetailAST ast) {
61 final boolean isInSwitchRule = ast.getParent().getType() == TokenTypes.SWITCH_RULE;
62
63 if (Objects.nonNull(ast.findFirstToken(TokenTypes.PARAMETERS))) {
64 final DetailAST parametersNode = ast.findFirstToken(TokenTypes.PARAMETERS);
65 TokenUtil.forEachChild(parametersNode, TokenTypes.PARAMETER_DEF, super::visitToken);
66 }
67 else if (!isInSwitchRule) {
68 super.visitToken(ast);
69 }
70 }
71
72 @Override
73 protected boolean mustCheckName(DetailAST ast) {
74 return true;
75 }
76
77 }