001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2022 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.whitespace;
021
022import java.util.Locale;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.TokenTypes;
028import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
029
030/**
031 * <p>
032 * Checks the padding of an empty for iterator; that is whether a white
033 * space is required at an empty for iterator, or such white space is
034 * forbidden. No check occurs if there is a line wrap at the iterator, as in
035 * </p>
036 * <pre>
037 * for (Iterator foo = very.long.line.iterator();
038 *     foo.hasNext();
039 *    )
040 * </pre>
041 * <ul>
042 * <li>
043 * Property {@code option} - Specify policy on how to pad an empty for iterator.
044 * Type is {@code com.puppycrawl.tools.checkstyle.checks.whitespace.PadOption}.
045 * Default value is {@code nospace}.
046 * </li>
047 * </ul>
048 * <p>
049 * To configure the check:
050 * </p>
051 * <pre>
052 * &lt;module name=&quot;EmptyForIteratorPad&quot;/&gt;
053 * </pre>
054 * <p>
055 * Example:
056 * </p>
057 * <pre>
058 * for (Iterator it = map.entrySet().iterator();  it.hasNext(););  // ok
059 * for (Iterator it = map.entrySet().iterator();  it.hasNext(); ); // violation since whitespace
060 *                                                                 //after semicolon
061 *
062 * for (Iterator foo = very.long.line.iterator();
063 *       foo.hasNext();
064 *      ); // ok
065 * </pre>
066 * <p>
067 * To configure the check to require white space at an empty for iterator:
068 * </p>
069 * <pre>
070 * &lt;module name=&quot;EmptyForIteratorPad&quot;&gt;
071 *   &lt;property name=&quot;option&quot; value=&quot;space&quot;/&gt;
072 * &lt;/module&gt;
073 * </pre>
074 * <p>
075 * Example:
076 * </p>
077 * <pre>
078 * for (Iterator it = map.entrySet().iterator();  it.hasNext();); // violation as there is no
079 *                                                                // whitespace after semicolon
080 *
081 * for (Iterator it = map.entrySet().iterator();  it.hasNext(); ); // ok
082 *
083 * for (Iterator foo = very.long.line.iterator();
084 *       foo.hasNext();
085 *      ); // violation as there  is no whitespace after semicolon
086 * </pre>
087 * <p>
088 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
089 * </p>
090 * <p>
091 * Violation Message Keys:
092 * </p>
093 * <ul>
094 * <li>
095 * {@code ws.followed}
096 * </li>
097 * <li>
098 * {@code ws.notFollowed}
099 * </li>
100 * </ul>
101 *
102 * @since 3.0
103 */
104@StatelessCheck
105public class EmptyForIteratorPadCheck
106    extends AbstractCheck {
107
108    /**
109     * A key is pointing to the warning message text in "messages.properties"
110     * file.
111     */
112    public static final String MSG_WS_FOLLOWED = "ws.followed";
113
114    /**
115     * A key is pointing to the warning message text in "messages.properties"
116     * file.
117     */
118    public static final String MSG_WS_NOT_FOLLOWED = "ws.notFollowed";
119
120    /** Semicolon literal. */
121    private static final String SEMICOLON = ";";
122
123    /** Specify policy on how to pad an empty for iterator. */
124    private PadOption option = PadOption.NOSPACE;
125
126    /**
127     * Setter to specify policy on how to pad an empty for iterator.
128     *
129     * @param optionStr string to decode option from
130     * @throws IllegalArgumentException if unable to decode
131     */
132    public void setOption(String optionStr) {
133        option = PadOption.valueOf(optionStr.trim().toUpperCase(Locale.ENGLISH));
134    }
135
136    @Override
137    public int[] getDefaultTokens() {
138        return getRequiredTokens();
139    }
140
141    @Override
142    public int[] getAcceptableTokens() {
143        return getRequiredTokens();
144    }
145
146    @Override
147    public int[] getRequiredTokens() {
148        return new int[] {TokenTypes.FOR_ITERATOR};
149    }
150
151    @Override
152    public void visitToken(DetailAST ast) {
153        if (!ast.hasChildren()) {
154            // empty for iterator. test pad after semi.
155            final DetailAST semi = ast.getPreviousSibling();
156            final int[] line = getLineCodePoints(semi.getLineNo() - 1);
157            final int after = semi.getColumnNo() + 1;
158            // don't check if at end of line
159            if (after < line.length) {
160                if (option == PadOption.NOSPACE
161                    && CommonUtil.isCodePointWhitespace(line, after)) {
162                    log(ast, MSG_WS_FOLLOWED, SEMICOLON);
163                }
164                else if (option == PadOption.SPACE
165                         && !CommonUtil.isCodePointWhitespace(line, after)) {
166                    log(ast, MSG_WS_NOT_FOLLOWED, SEMICOLON);
167                }
168            }
169        }
170    }
171
172}