View Javadoc
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.api;
21  
22  /**
23   * An interface of Checkstyle's AST nodes for traversing trees generated from the
24   * Java code. The main purpose of this interface is to abstract away ANTLR
25   * specific classes from API package so other libraries won't require it.
26   *
27   * @see <a href="https://www.antlr.org/">ANTLR Website</a>
28   */
29  public interface DetailAST {
30  
31      /**
32       * Returns the number of child nodes one level below this node. That is,
33       * does not recurse down the tree.
34       *
35       * @return the number of child nodes
36       */
37      int getChildCount();
38  
39      /**
40       * Returns the number of direct child tokens that have the specified type.
41       *
42       * @param type the token type to match
43       * @return the number of matching token
44       */
45      int getChildCount(int type);
46  
47      /**
48       * Returns the parent token.
49       *
50       * @return the parent token
51       */
52      DetailAST getParent();
53  
54      /**
55       * Gets the text of this AST.
56       *
57       * @return the text.
58       */
59      String getText();
60  
61      /**
62       * Gets the type of this AST.
63       *
64       * @return the type.
65       */
66      int getType();
67  
68      /**
69       * Gets line number.
70       *
71       * @return the line number
72       */
73      int getLineNo();
74  
75      /**
76       * Gets column number.
77       *
78       * @return the column number
79       */
80      int getColumnNo();
81  
82      /**
83       * Gets the last child node.
84       *
85       * @return the last child node
86       */
87      DetailAST getLastChild();
88  
89      /**
90       * Checks if this branch of the parse tree contains a token
91       * of the provided type.
92       *
93       * @param type a TokenType
94       * @return true if and only if this branch (including this node)
95       *     contains a token of type {@code type}.
96       * @deprecated
97       *      Usage of this method is no longer accepted. We encourage
98       *      traversal of subtrees to be written per the needs of each check
99       *      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 }