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|
use ra_syntax::{
SourceFile, TextUnit,
algo::find_token_at_offset,
SyntaxKind::{self, *},
ast::AstNode,
};
pub fn matching_brace(file: &SourceFile, offset: TextUnit) -> Option<TextUnit> {
const BRACES: &[SyntaxKind] =
&[L_CURLY, R_CURLY, L_BRACK, R_BRACK, L_PAREN, R_PAREN, L_ANGLE, R_ANGLE];
let (brace_node, brace_idx) = find_token_at_offset(file.syntax(), offset)
.filter_map(|node| {
let idx = BRACES.iter().position(|&brace| brace == node.kind())?;
Some((node, idx))
})
.next()?;
let parent = brace_node.parent();
let matching_kind = BRACES[brace_idx ^ 1];
let matching_node = parent.children_with_tokens().find(|node| node.kind() == matching_kind)?;
Some(matching_node.range().start())
}
#[cfg(test)]
mod tests {
use test_utils::{add_cursor, assert_eq_text, extract_offset};
use super::*;
#[test]
fn test_matching_brace() {
fn do_check(before: &str, after: &str) {
let (pos, before) = extract_offset(before);
let file = SourceFile::parse(&before);
let new_pos = match matching_brace(&file, pos) {
None => pos,
Some(pos) => pos,
};
let actual = add_cursor(&before, new_pos);
assert_eq_text!(after, &actual);
}
do_check("struct Foo { a: i32, }<|>", "struct Foo <|>{ a: i32, }");
}
}
|
