{"ast_node_type":"variable","tokens":[{"end":96,"kind":"keyword","start":0,"text":"let"}]}
                    let (al, ar) = args.split_at(ellipsis.map_or(args.len(), |it| it as usize));
                Pat::Tuple { args, ellipsis } => {
                    let field_count = match self.result[tgt_pat].kind(Interner) {