mirror of
https://github.com/rust-lang/rust-analyzer
synced 2025-01-20 00:54:45 +00:00
85633656df
E.g. in
```
let foo = 1u32;
if true {
<|>foo;
}
```
the hover shows `()`, the type of the whole if expression, instead of the more
sensible `u32`. The reason for this was that the search for an expression was
slightly left-biased: When on the edge between two tokens, it first looked at
all ancestors of the left token and then of the right token. Instead merge the
ancestors in ascending order, so that we get the smaller of the two possible
expressions.
63 lines
2.3 KiB
Rust
63 lines
2.3 KiB
Rust
pub mod visit;
|
|
|
|
use itertools::Itertools;
|
|
|
|
use crate::{SyntaxNode, TextRange, TextUnit, AstNode, Direction, SyntaxToken, SyntaxElement};
|
|
|
|
pub use rowan::TokenAtOffset;
|
|
|
|
pub fn find_token_at_offset(node: &SyntaxNode, offset: TextUnit) -> TokenAtOffset<SyntaxToken> {
|
|
match node.0.token_at_offset(offset) {
|
|
TokenAtOffset::None => TokenAtOffset::None,
|
|
TokenAtOffset::Single(n) => TokenAtOffset::Single(n.into()),
|
|
TokenAtOffset::Between(l, r) => TokenAtOffset::Between(l.into(), r.into()),
|
|
}
|
|
}
|
|
|
|
/// Returns ancestors of the node at the offset, sorted by length. This should
|
|
/// do the right thing at an edge, e.g. when searching for expressions at `{
|
|
/// <|>foo }` we will get the name reference instead of the whole block, which
|
|
/// we would get if we just did `find_token_at_offset(...).flat_map(|t|
|
|
/// t.parent().ancestors())`.
|
|
pub fn ancestors_at_offset(
|
|
node: &SyntaxNode,
|
|
offset: TextUnit,
|
|
) -> impl Iterator<Item = &SyntaxNode> {
|
|
find_token_at_offset(node, offset)
|
|
.map(|token| token.parent().ancestors())
|
|
.kmerge_by(|node1, node2| node1.range().len() < node2.range().len())
|
|
}
|
|
|
|
/// Finds a node of specific Ast type at offset. Note that this is slightly
|
|
/// imprecise: if the cursor is strictly between two nodes of the desired type,
|
|
/// as in
|
|
///
|
|
/// ```no-run
|
|
/// struct Foo {}|struct Bar;
|
|
/// ```
|
|
///
|
|
/// then the shorter node will be silently preferred.
|
|
pub fn find_node_at_offset<N: AstNode>(syntax: &SyntaxNode, offset: TextUnit) -> Option<&N> {
|
|
ancestors_at_offset(syntax, offset).find_map(N::cast)
|
|
}
|
|
|
|
/// Finds the first sibling in the given direction which is not `trivia`
|
|
pub fn non_trivia_sibling(element: SyntaxElement, direction: Direction) -> Option<SyntaxElement> {
|
|
return match element {
|
|
SyntaxElement::Node(node) => node.siblings_with_tokens(direction).skip(1).find(not_trivia),
|
|
SyntaxElement::Token(token) => {
|
|
token.siblings_with_tokens(direction).skip(1).find(not_trivia)
|
|
}
|
|
};
|
|
|
|
fn not_trivia(element: &SyntaxElement) -> bool {
|
|
match element {
|
|
SyntaxElement::Node(_) => true,
|
|
SyntaxElement::Token(token) => !token.kind().is_trivia(),
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn find_covering_element(root: &SyntaxNode, range: TextRange) -> SyntaxElement {
|
|
root.0.covering_node(range).into()
|
|
}
|