Function Append

cpp/src/arrow/array/builder_union.h:156–165

\brief Append an element to the UnionArray. This must be followed by an append to the appropriate child builder. \param[in] next_type type_id of the child to which the next value will be appended. The corresponding child builder must be appended to independently after this method is called.

  /// The corresponding child builder must be appended to independently after this method
  /// is called.
  Status Append(int8_t next_type) {
    ARROW_RETURN_NOT_OK(types_builder_.Append(next_type));
    if (type_id_to_children_[next_type]->length() == kListMaximumElements) {
      return Status::CapacityError(
          "a dense UnionArray cannot contain more than 2^31 - 1 elements from a single "
          "child");
    }
    auto offset = static_cast<int32_t>(type_id_to_children_[next_type]->length());
    return offsets_builder_.Append(offset);
  }

  Status AppendArraySlice(const ArraySpan& array, int64_t offset,
                          int64_t length) override;