3 SourceFile, SyntaxKind, TextSize, T,
6 // Feature: Matching Brace
8 // If the cursor is on any brace (`<>(){}[]||`) which is a part of a brace-pair,
9 // moves cursor to the matching brace. It uses the actual parser to determine
10 // braces, so it won't confuse generics with comparisons.
13 // | Editor | Action Name
15 // | VS Code | **Rust Analyzer: Find matching brace**
18 // image::https://user-images.githubusercontent.com/48062697/113065573-04298180-91b1-11eb-8dec-d4e2a202f304.gif[]
19 pub(crate) fn matching_brace(file: &SourceFile, offset: TextSize) -> Option<TextSize> {
20 const BRACES: &[SyntaxKind] =
21 &[T!['{'], T!['}'], T!['['], T![']'], T!['('], T![')'], T![<], T![>], T![|], T![|]];
22 let (brace_token, brace_idx) = file
24 .token_at_offset(offset)
26 let idx = BRACES.iter().position(|&brace| brace == node.kind())?;
30 let parent = brace_token.parent()?;
31 if brace_token.kind() == T![|] && !ast::ParamList::can_cast(parent.kind()) {
32 cov_mark::hit!(pipes_not_braces);
35 let matching_kind = BRACES[brace_idx ^ 1];
36 let matching_node = parent
37 .children_with_tokens()
38 .filter_map(|it| it.into_token())
39 .find(|node| node.kind() == matching_kind && node != &brace_token)?;
40 Some(matching_node.text_range().start())
45 use test_utils::{add_cursor, assert_eq_text, extract_offset};
50 fn test_matching_brace() {
51 fn do_check(before: &str, after: &str) {
52 let (pos, before) = extract_offset(before);
53 let parse = SourceFile::parse(&before);
54 let new_pos = match matching_brace(&parse.tree(), pos) {
58 let actual = add_cursor(&before, new_pos);
59 assert_eq_text!(after, &actual);
62 do_check("struct Foo { a: i32, }$0", "struct Foo $0{ a: i32, }");
63 do_check("fn main() { |x: i32|$0 x * 2;}", "fn main() { $0|x: i32| x * 2;}");
64 do_check("fn main() { $0|x: i32| x * 2;}", "fn main() { |x: i32$0| x * 2;}");
66 "fn func(x) { return (2 * (x + 3)$0) + 5;}",
67 "fn func(x) { return $0(2 * (x + 3)) + 5;}",
71 cov_mark::check!(pipes_not_braces);
73 "fn main() { match 92 { 1 | 2 |$0 3 => 92 } }",
74 "fn main() { match 92 { 1 | 2 |$0 3 => 92 } }",