68 lines
1.9 KiB
Rust
68 lines
1.9 KiB
Rust
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use ra_syntax::{
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File, TextRange, SyntaxKind, SyntaxNode, SyntaxNodeRef,
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ast::{self, AstNode},
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};
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use crate::FileId;
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use crate::db::SyntaxDatabase;
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/// SyntaxPtr is a cheap `Copy` id which identifies a particular syntax node,
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/// without retainig syntax tree in memory. You need to explicitelly `resovle`
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/// `SyntaxPtr` to get a `SyntaxNode`
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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pub(crate) struct SyntaxPtr {
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file_id: FileId,
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local: LocalSyntaxPtr,
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}
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impl SyntaxPtr {
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pub(crate) fn new(file_id: FileId, node: SyntaxNodeRef) -> SyntaxPtr {
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let local = LocalSyntaxPtr::new(node);
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SyntaxPtr { file_id, local }
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}
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pub(crate) fn resolve(self, db: &impl SyntaxDatabase) -> SyntaxNode {
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let syntax = db.file_syntax(self.file_id);
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self.local.resolve(&syntax)
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}
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}
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/// A pionter to a syntax node inside a file.
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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struct LocalSyntaxPtr {
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range: TextRange,
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kind: SyntaxKind,
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}
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impl LocalSyntaxPtr {
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fn new(node: SyntaxNodeRef) -> LocalSyntaxPtr {
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LocalSyntaxPtr {
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range: node.range(),
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kind: node.kind(),
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}
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}
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fn resolve(self, file: &File) -> SyntaxNode {
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let mut curr = file.syntax();
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loop {
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if curr.range() == self.range && curr.kind() == self.kind {
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return curr.owned();
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}
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curr = curr.children()
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.find(|it| self.range.is_subrange(&it.range()))
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.unwrap_or_else(|| panic!("can't resovle local ptr to SyntaxNode: {:?}", self))
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}
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}
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}
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#[test]
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fn test_local_syntax_ptr() {
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let file = File::parse("struct Foo { f: u32, }");
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let field = file.syntax().descendants().find_map(ast::NamedFieldDef::cast).unwrap();
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let ptr = LocalSyntaxPtr::new(field.syntax());
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let field_syntax = ptr.resolve(&file);
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assert_eq!(field.syntax(), field_syntax);
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}
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