1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2025 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.api;
21
22 import javax.annotation.Nullable;
23
24 /**
25 * An interface of Checkstyle's AST nodes for traversing trees generated from the
26 * Java code. The main purpose of this interface is to abstract away ANTLR
27 * specific classes from API package so other libraries won't require it.
28 *
29 * @see <a href="https://www.antlr.org/">ANTLR Website</a>
30 */
31 public interface DetailAST {
32
33 /**
34 * Returns the number of child nodes one level below this node. That is,
35 * does not recurse down the tree.
36 *
37 * @return the number of child nodes
38 */
39 int getChildCount();
40
41 /**
42 * Returns the number of direct child tokens that have the specified type.
43 *
44 * @param type the token type to match
45 * @return the number of matching token
46 */
47 int getChildCount(int type);
48
49 /**
50 * Returns the parent token.
51 *
52 * @return the parent token
53 */
54 DetailAST getParent();
55
56 /**
57 * Gets the text of this AST.
58 *
59 * @return the text.
60 */
61 String getText();
62
63 /**
64 * Gets the type of this AST.
65 *
66 * @return the type.
67 */
68 int getType();
69
70 /**
71 * Gets line number.
72 *
73 * @return the line number
74 */
75 int getLineNo();
76
77 /**
78 * Gets column number.
79 *
80 * @return the column number
81 */
82 int getColumnNo();
83
84 /**
85 * Gets the last child node.
86 *
87 * @return the last child node
88 */
89 DetailAST getLastChild();
90
91 /**
92 * Checks if this branch of the parse tree contains a token
93 * of the provided type.
94 *
95 * @param type a TokenType
96 * @return true if and only if this branch (including this node)
97 * contains a token of type {@code type}.
98 * @deprecated
99 * Usage of this method is no longer accepted. We encourage
100 * traversal of subtrees to be written per the needs of each check
101 * to avoid unintended side effects.
102 * @noinspection DeprecatedIsStillUsed, RedundantSuppression
103 * @noinspectionreason DeprecatedIsStillUsed - Method used in unit testing
104 * @noinspectionreason RedundantSuppression - Inspections shows false positive for
105 * redundant suppression, see
106 * <a href="https://github.com/checkstyle/checkstyle/issues/12359">here</a>
107 * for more details.
108 */
109 @Deprecated(since = "8.43")
110 boolean branchContains(int type);
111
112 /**
113 * Returns the previous sibling or null if no such sibling exists.
114 *
115 * @return the previous sibling or null if no such sibling exists.
116 */
117 DetailAST getPreviousSibling();
118
119 /**
120 * Returns the first child token that makes a specified type.
121 *
122 * @param type the token type to match
123 * @return the matching token, or null if no match
124 */
125 @Nullable
126 DetailAST findFirstToken(int type);
127
128 /**
129 * Get the next sibling in line after this one.
130 *
131 * @return the next sibling or null if none.
132 */
133 DetailAST getNextSibling();
134
135 /**
136 * Get the first child of this AST.
137 *
138 * @return the first child or null if none.
139 */
140 DetailAST getFirstChild();
141
142 /**
143 * Get number of children of this AST.
144 *
145 * @return the number of children.
146 * @deprecated This method will be removed in a future release.
147 * Use {@link #getChildCount()} instead.
148 */
149 @Deprecated(since = "8.30")
150 int getNumberOfChildren();
151
152 /**
153 * Returns whether this AST has any children.
154 *
155 * @return {@code true} if this AST has any children.
156 */
157 boolean hasChildren();
158 }