{"ast_node_type":"variable","tokens":[{"end":98,"kind":"keyword","start":0,"text":"let"}]}
                let base_ty = self.infer_expr_inner(*base, &Expectation::none(), ExprIsRead::Yes);
            Expr::Index { base, index } => {
                let index_ty = self.infer_expr(*index, &Expectation::none(), ExprIsRead::Yes);