Source code

001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2025 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.api;
021
022/**
023 * An interface of Checkstyle's AST nodes for traversing trees generated from the
024 * Java code. The main purpose of this interface is to abstract away ANTLR
025 * specific classes from API package so other libraries won't require it.
026 *
027 * @see <a href="https://www.antlr.org/">ANTLR Website</a>
028 */
029public interface DetailAST {
030
031 /**
032 * Returns the number of child nodes one level below this node. That is,
033 * does not recurse down the tree.
034 *
035 * @return the number of child nodes
036 */
037 int getChildCount();
038
039 /**
040 * Returns the number of direct child tokens that have the specified type.
041 *
042 * @param type the token type to match
043 * @return the number of matching token
044 */
045 int getChildCount(int type);
046
047 /**
048 * Returns the parent token.
049 *
050 * @return the parent token
051 */
052 DetailAST getParent();
053
054 /**
055 * Gets the text of this AST.
056 *
057 * @return the text.
058 */
059 String getText();
060
061 /**
062 * Gets the type of this AST.
063 *
064 * @return the type.
065 */
066 int getType();
067
068 /**
069 * Gets line number.
070 *
071 * @return the line number
072 */
073 int getLineNo();
074
075 /**
076 * Gets column number.
077 *
078 * @return the column number
079 */
080 int getColumnNo();
081
082 /**
083 * Gets the last child node.
084 *
085 * @return the last child node
086 */
087 DetailAST getLastChild();
088
089 /**
090 * Checks if this branch of the parse tree contains a token
091 * of the provided type.
092 *
093 * @param type a TokenType
094 * @return true if and only if this branch (including this node)
095 * contains a token of type {@code type}.
096 * @deprecated
097 * Usage of this method is no longer accepted. We encourage
098 * traversal of subtrees to be written per the needs of each check
099 * to avoid unintended side effects.
100 * @noinspection DeprecatedIsStillUsed, RedundantSuppression
101 * @noinspectionreason DeprecatedIsStillUsed - Method used in unit testing
102 * @noinspectionreason RedundantSuppression - Inspections shows false positive for
103 * redundant suppression, see
104 * <a href="https://github.com/checkstyle/checkstyle/issues/12359">here</a>
105 * for more details.
106 */
107 @Deprecated(since = "8.43")
108 boolean branchContains(int type);
109
110 /**
111 * Returns the previous sibling or null if no such sibling exists.
112 *
113 * @return the previous sibling or null if no such sibling exists.
114 */
115 DetailAST getPreviousSibling();
116
117 /**
118 * Returns the first child token that makes a specified type.
119 *
120 * @param type the token type to match
121 * @return the matching token, or null if no match
122 */
123 DetailAST findFirstToken(int type);
124
125 /**
126 * Get the next sibling in line after this one.
127 *
128 * @return the next sibling or null if none.
129 */
130 DetailAST getNextSibling();
131
132 /**
133 * Get the first child of this AST.
134 *
135 * @return the first child or null if none.
136 */
137 DetailAST getFirstChild();
138
139 /**
140 * Get number of children of this AST.
141 *
142 * @return the number of children.
143 * @deprecated This method will be removed in a future release.
144 * Use {@link #getChildCount()} instead.
145 */
146 @Deprecated(since = "8.30")
147 int getNumberOfChildren();
148
149 /**
150 * Returns whether this AST has any children.
151 *
152 * @return {@code true} if this AST has any children.
153 */
154 boolean hasChildren();
155}