{"ast_node_type":"variable","tokens":[{"end":53,"kind":"keyword","start":0,"text":"let"}]}
        let ribs = &self.label_ribs[rib_index + 1..];
    fn is_label_valid_from_rib(&self, rib_index: usize) -> bool {
        ribs.iter().all(|rib| !rib.kind.is_label_barrier())