{"ast_node_type":"variable","tokens":[{"end":90,"kind":"keyword","start":0,"text":"let"}]}
            let postfix = if unicode_width::UnicodeWidthChar::width(c).unwrap_or(1) == 0 {
            let mut err = dcx.struct_span_err(span, format!("non-ASCII character in {desc}"));
                format!(" but is {c:?}")