{"ast_node_type":"variable","tokens":[{"end":78,"kind":"keyword","start":0,"text":"let"}]}
            let x_expr = self.expr_ident(gen_future_span, x_ident, x_pat_hid);
            let (x_pat, x_pat_hid) = self.pat_ident(gen_future_span, x_ident);
            let ready_field = self.single_pat_field(gen_future_span, x_pat);