Function PrintDiff

cpp/src/arrow/compare.cc:1075–1116

Status PrintDiff(const Array& left, const Array& right, std::ostream* os);

Status PrintDiff(const Array& left, const Array& right, int64_t left_offset,
                 int64_t left_length, int64_t right_offset, int64_t right_length,
                 std::ostream* os) {
  if (os == nullptr) {
    return Status::OK();
  }

  if (!left.type()->Equals(right.type())) {
    *os << "# Array types differed: " << *left.type() << " vs " << *right.type()
        << std::endl;
    return Status::OK();
  }

  if (left.type()->id() == Type::DICTIONARY) {
    *os << "# Dictionary arrays differed" << std::endl;

    const auto& left_dict = checked_cast<const DictionaryArray&>(left);
    const auto& right_dict = checked_cast<const DictionaryArray&>(right);

    *os << "## dictionary diff";
    auto pos = os->tellp();
    RETURN_NOT_OK(PrintDiff(*left_dict.dictionary(), *right_dict.dictionary(), os));
    if (os->tellp() == pos) {
      *os << std::endl;
    }

    *os << "## indices diff";
    pos = os->tellp();
    RETURN_NOT_OK(PrintDiff(*left_dict.indices(), *right_dict.indices(), os));
    if (os->tellp() == pos) {
      *os << std::endl;
    }
    return Status::OK();
  }

  const auto left_slice = left.Slice(left_offset, left_length);
  const auto right_slice = right.Slice(right_offset, right_length);
  ARROW_ASSIGN_OR_RAISE(auto edits,
                        Diff(*left_slice, *right_slice, default_memory_pool()));
  ARROW_ASSIGN_OR_RAISE(auto formatter, MakeUnifiedDiffFormatter(*left.type(), os));
  return formatter(*edits, *left_slice, *right_slice);
}

Status PrintDiff(const Array& left, const Array& right, std::ostream* os) {
  return PrintDiff(left, right, 0, left.length(), 0, right.length(), os);