1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 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 * <p>
30 * Checks lambda parameter names.
31 * </p>
32 * <ul>
33 * <li>
34 * Property {@code format} - Sets the pattern to match valid identifiers.
35 * Type is {@code java.util.regex.Pattern}.
36 * Default value is {@code "^([a-z][a-zA-Z0-9]*|_)$"}.
37 * </li>
38 * </ul>
39 * <p>
40 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
41 * </p>
42 * <p>
43 * Violation Message Keys:
44 * </p>
45 * <ul>
46 * <li>
47 * {@code name.invalidPattern}
48 * </li>
49 * </ul>
50 *
51 * @since 8.11
52 */
53 public class LambdaParameterNameCheck extends AbstractNameCheck {
54
55 /** Creates new instance of {@code LambdaParameterNameCheck}. */
56 public LambdaParameterNameCheck() {
57 super("^([a-z][a-zA-Z0-9]*|_)$");
58 }
59
60 @Override
61 public int[] getDefaultTokens() {
62 return getRequiredTokens();
63 }
64
65 @Override
66 public int[] getAcceptableTokens() {
67 return getRequiredTokens();
68 }
69
70 @Override
71 public int[] getRequiredTokens() {
72 return new int[] {
73 TokenTypes.LAMBDA,
74 };
75 }
76
77 @Override
78 public void visitToken(DetailAST ast) {
79 final boolean isInSwitchRule = ast.getParent().getType() == TokenTypes.SWITCH_RULE;
80
81 if (Objects.nonNull(ast.findFirstToken(TokenTypes.PARAMETERS))) {
82 final DetailAST parametersNode = ast.findFirstToken(TokenTypes.PARAMETERS);
83 TokenUtil.forEachChild(parametersNode, TokenTypes.PARAMETER_DEF, super::visitToken);
84 }
85 else if (!isInSwitchRule) {
86 super.visitToken(ast);
87 }
88 }
89
90 @Override
91 protected boolean mustCheckName(DetailAST ast) {
92 return true;
93 }
94
95 }