1 /*
2 * Copyright (c) 2011-2025 Yegor Bugayenko
3 *
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met: 1) Redistributions of source code must retain the above
9 * copyright notice, this list of conditions and the following
10 * disclaimer. 2) Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following
12 * disclaimer in the documentation and/or other materials provided
13 * with the distribution. 3) Neither the name of the Qulice.com nor
14 * the names of its contributors may be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
20 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29 * OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31 package com.qulice.checkstyle;
32
33 import com.puppycrawl.tools.checkstyle.api.DetailAST;
34 import java.util.stream.Stream;
35
36 /**
37 * Utility class which simplifies traversing DetailAST objects.
38 *
39 * DetailAST APIs for working with child nodes require writing
40 * imperative code, which generally looks less readable then
41 * declarative Stream manipulations. This class integrates DetailAST
42 * with Java Streams.
43 *
44 * @since 1.0
45 */
46 class ChildStream {
47 /**
48 * Node, whose children will be traversed by this ChildStream object.
49 */
50 private final DetailAST node;
51
52 /**
53 * Creates a new child stream factory.
54 *
55 * @param node Node which will used by this object.
56 */
57 ChildStream(final DetailAST node) {
58 this.node = node;
59 }
60
61 /**
62 * Creates a new stream which sequentially yields all
63 * children. Any two streams returned by this method are
64 * independent.
65 *
66 * Implementation may be simplified using Stream.iterate when Java 8 support
67 * is dropped.
68 *
69 * @return Stream of children
70 */
71 Stream<DetailAST> children() {
72 final Stream.Builder<DetailAST> builder = Stream.builder();
73 DetailAST child = this.node.getFirstChild();
74 while (child != null) {
75 builder.accept(child);
76 child = child.getNextSibling();
77 }
78 return builder.build();
79 }
80 }