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1   ///////////////////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3   // Copyright (C) 2001-2026 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.whitespace;
21  
22  import java.util.Locale;
23  
24  import com.puppycrawl.tools.checkstyle.StatelessCheck;
25  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
26  import com.puppycrawl.tools.checkstyle.api.DetailAST;
27  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
28  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
29  
30  /**
31   * <div>
32   * Checks the padding of an empty for iterator; that is whether a white
33   * space is required at an empty for iterator, or such white space is
34   * forbidden. No check occurs if there is a line wrap at the iterator, as in
35   * </div>
36   * {@snippet lang="text" :
37   * for (Iterator foo = very.long.line.iterator();
38   *     foo.hasNext();
39   *    )
40   * }
41   *
42   * @since 3.0
43   */
44  @StatelessCheck
45  public class EmptyForIteratorPadCheck
46      extends AbstractCheck {
47  
48      /**
49       * A key is pointing to the warning message text in "messages.properties"
50       * file.
51       */
52      public static final String MSG_WS_FOLLOWED = "ws.followed";
53  
54      /**
55       * A key is pointing to the warning message text in "messages.properties"
56       * file.
57       */
58      public static final String MSG_WS_NOT_FOLLOWED = "ws.notFollowed";
59  
60      /** Semicolon literal. */
61      private static final String SEMICOLON = ";";
62  
63      /** Specify policy on how to pad an empty for iterator. */
64      private PadOption option = PadOption.NOSPACE;
65  
66      /**
67       * Creates a new {@code EmptyForIteratorPadCheck} instance.
68       */
69      public EmptyForIteratorPadCheck() {
70          // no code by default
71      }
72  
73      /**
74       * Setter to specify policy on how to pad an empty for iterator.
75       *
76       * @param optionStr string to decode option from
77       * @throws IllegalArgumentException if unable to decode
78       * @since 3.0
79       */
80      public void setOption(String optionStr) {
81          option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
82      }
83  
84      @Override
85      public int[] getDefaultTokens() {
86          return getRequiredTokens();
87      }
88  
89      @Override
90      public int[] getAcceptableTokens() {
91          return getRequiredTokens();
92      }
93  
94      @Override
95      public int[] getRequiredTokens() {
96          return new int[] {TokenTypes.FOR_ITERATOR};
97      }
98  
99      @Override
100     public void visitToken(DetailAST ast) {
101         if (!ast.hasChildren()) {
102             // empty for iterator. test pad after semi.
103             final DetailAST semi = ast.getPreviousSibling();
104             final int[] line = getLineCodePoints(semi.getLineNo() - 1);
105             final int after = semi.getColumnNo() + 1;
106             // don't check if at end of line
107             if (after < line.length) {
108                 if (option == PadOption.NOSPACE
109                     && CommonUtil.isCodePointWhitespace(line, after)) {
110                     log(ast, MSG_WS_FOLLOWED, SEMICOLON);
111                 }
112                 else if (option == PadOption.SPACE
113                          && !CommonUtil.isCodePointWhitespace(line, after)) {
114                     log(ast, MSG_WS_NOT_FOLLOWED, SEMICOLON);
115                 }
116             }
117         }
118     }
119 
120 }