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 * <div>
30 * Checks lambda parameter names.
31 * </div>
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]*|_)$"}.
37 * </li>
38 * </ul>
39 *
40 * <p>
41 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
42 * </p>
43 *
44 * <p>
45 * Violation Message Keys:
46 * </p>
47 * <ul>
48 * <li>
49 * {@code name.invalidPattern}
50 * </li>
51 * </ul>
52 *
53 * @since 8.11
54 */
55 public class LambdaParameterNameCheck extends AbstractNameCheck {
56
57 /** Creates new instance of {@code LambdaParameterNameCheck}. */
58 public LambdaParameterNameCheck() {
59 super("^([a-z][a-zA-Z0-9]*|_)$");
60 }
61
62 @Override
63 public int[] getDefaultTokens() {
64 return getRequiredTokens();
65 }
66
67 @Override
68 public int[] getAcceptableTokens() {
69 return getRequiredTokens();
70 }
71
72 @Override
73 public int[] getRequiredTokens() {
74 return new int[] {
75 TokenTypes.LAMBDA,
76 };
77 }
78
79 @Override
80 public void visitToken(DetailAST ast) {
81 final boolean isInSwitchRule = ast.getParent().getType() == TokenTypes.SWITCH_RULE;
82
83 if (Objects.nonNull(ast.findFirstToken(TokenTypes.PARAMETERS))) {
84 final DetailAST parametersNode = ast.findFirstToken(TokenTypes.PARAMETERS);
85 TokenUtil.forEachChild(parametersNode, TokenTypes.PARAMETER_DEF, super::visitToken);
86 }
87 else if (!isInSwitchRule) {
88 super.visitToken(ast);
89 }
90 }
91
92 @Override
93 protected boolean mustCheckName(DetailAST ast) {
94 return true;
95 }
96
97 }