romainfrancois commented on a change in pull request #7514: URL: https://github.com/apache/arrow/pull/7514#discussion_r444308097
########## File path: r/src/array_from_vector.cpp ########## @@ -1067,12 +1110,22 @@ std::shared_ptr<arrow::DataType> InferArrowTypeFromVector<VECSXP>(SEXP x) { if (Rf_inherits(x, "data.frame")) { return InferArrowTypeFromDataFrame(x); } else { - if (XLENGTH(x) == 0) { - Rcpp::stop( - "Requires at least one element to infer the values' type of a list vector"); - } + SEXP ptype = Rf_getAttrib(x, symbols::ptype); + if (ptype == R_NilValue) { Review comment: Counting 6 cases of `Rf_isNull()` and 3 cases of `== R_NilValue` I'll switch to `Rf_isNull()` here ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org