{"ast_node_type":"variable","tokens":[{"end":58,"kind":"keyword","start":0,"text":"if"}]}
            if let Some((ref mut fail, x_ty, x_span)) = *x
        let demand_eqtype = |x: &mut _, y| {
                && let Err(mut err) = self.demand_eqtype_pat_diag(x_span, expected, x_ty, ti)