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**
17 pub(crate) fn matching_brace(file: &SourceFile, offset: TextSize) -> Option<TextSize> {
18 const BRACES: &[SyntaxKind] =
19 &[T!['{'], T!['}'], T!['['], T![']'], T!['('], T![')'], T![<], T![>], T![|], T![|]];
20 let (brace_token, brace_idx) = file
22 .token_at_offset(offset)
24 let idx = BRACES.iter().position(|&brace| brace == node.kind())?;
28 let parent = brace_token.parent();
29 if brace_token.kind() == T![|] && !ast::ParamList::can_cast(parent.kind()) {
30 cov_mark::hit!(pipes_not_braces);
33 let matching_kind = BRACES[brace_idx ^ 1];
34 let matching_node = parent
35 .children_with_tokens()
36 .filter_map(|it| it.into_token())
37 .find(|node| node.kind() == matching_kind && node != &brace_token)?;
38 Some(matching_node.text_range().start())
43 use test_utils::{add_cursor, assert_eq_text, extract_offset};
48 fn test_matching_brace() {
49 fn do_check(before: &str, after: &str) {
50 let (pos, before) = extract_offset(before);
51 let parse = SourceFile::parse(&before);
52 let new_pos = match matching_brace(&parse.tree(), pos) {
56 let actual = add_cursor(&before, new_pos);
57 assert_eq_text!(after, &actual);
60 do_check("struct Foo { a: i32, }$0", "struct Foo $0{ a: i32, }");
61 do_check("fn main() { |x: i32|$0 x * 2;}", "fn main() { $0|x: i32| x * 2;}");
62 do_check("fn main() { $0|x: i32| x * 2;}", "fn main() { |x: i32$0| x * 2;}");
65 cov_mark::check!(pipes_not_braces);
67 "fn main() { match 92 { 1 | 2 |$0 3 => 92 } }",
68 "fn main() { match 92 { 1 | 2 |$0 3 => 92 } }",