Function effective_using_bindings_for_name 

pub fn effective_using_bindings_for_name(
    visibility: &VisibilityIndex<'_>,
    imports: &OrdinaryTypeImportCell,
    file: &ProjectFile,
    node: Node<'_>,
    source: &str,
    name: &str,
) -> Arc<[OrdinaryTypeImport]> 

node may be any node of file’s tree; the projection reaches the tree root itself when it needs one. Node::parent re-descends from the root on every call (tree-sitter 0.24+), so climbing to the root eagerly at each call site cost a near-full-AST scan per reference on a large flat file (#1927); a name with no candidate bindings never pays for it.