Function get_row_as_string

matlab/src/cpp/arrow/matlab/tabular/get_row_as_string.h:39–78

template <typename TabularType>
arrow::Result<std::string> get_row_as_string(
    const std::shared_ptr<TabularType>& tabular_object, const int64_t matlab_row_index) {
  std::stringstream ss;
  const int64_t row_index = matlab_row_index - 1;
  if (row_index >= tabular_object->num_rows() || row_index < 0) {
    ss << "Invalid Row Index: " << matlab_row_index;
    return arrow::Status::Invalid(ss.str());
  }

  const auto opts = make_pretty_print_options();
  const auto num_columns = tabular_object->num_columns();
  const auto& columns = tabular_object->columns();

  for (int32_t i = 0; i < num_columns; ++i) {
    const auto& column = columns[i];
    const auto type_id = column->type()->id();
    if (arrow::is_primitive(type_id) || arrow::is_string(type_id)) {
      auto slice = column->Slice(row_index, 1);
      ARROW_RETURN_NOT_OK(arrow::PrettyPrint(*slice, opts, &ss));
    } else if (type_id == arrow::Type::type::STRUCT) {
      // Use <Struct> as a placeholder since we don't have a good
      // way to display StructArray elements horizontally on screen.
      ss << "<Struct>";
    } else if (type_id == arrow::Type::type::LIST) {
      // Use <List> as a placeholder since we don't have a good
      // way to display ListArray elements horizontally on screen.
      ss << "<List>";
    } else {
      return arrow::Status::NotImplemented("Datatype " + column->type()->ToString() +
                                           "is not currently supported for display.");
    }

    if (i + 1 < num_columns) {
      // Only add the delimiter if there is at least
      // one more element to print.
      ss << " | ";
    }
  }
  return ss.str();
}
}  // namespace arrow::matlab::tabular