{"ast_node_type":"variable","tokens":[{"end":202,"kind":"keyword","start":0,"text":"let"}]}
                let is_ctor = |f: &Expr<'_>| matches!(f.kind, hir::ExprKind::Path(hir::QPath::Resolved(_, path)) if matches!(path.res, rustc_hir::def::Res::Def(rustc_hir::def::DefKind::Ctor(_, _), _)));
            hir::ExprKind::Call(ref f, args) => {
                let succ =