{"ast_node_type":"function","tokens":[{"end":69,"kind":"keyword","start":0,"text":"let"}]}
                let tt_fn = |link| MdTree::Link { disp: link, link };
            (_, Newline | Whitespace) if loop_buf.starts_with(ANC_S) => {
                let ret = parse_simple_pat(loop_buf, ANC_S, ANC_E, Po::None, tt_fn);