Method ProcessUnion

cpp/src/arrow/c/bridge.cc:1352–1386

  }

  Status ProcessUnion() {
    RETURN_NOT_OK(f_parser_.CheckHasNext());
    UnionMode::type mode;
    switch (f_parser_.Next()) {
      case 'd':
        mode = UnionMode::DENSE;
        break;
      case 's':
        mode = UnionMode::SPARSE;
        break;
      default:
        return f_parser_.Invalid();
    }
    RETURN_NOT_OK(f_parser_.CheckNext(':'));
    ARROW_ASSIGN_OR_RAISE(auto type_codes, f_parser_.ParseInts<int8_t>(f_parser_.Rest()));
    ARROW_ASSIGN_OR_RAISE(auto fields, MakeChildFields());
    if (fields.size() != type_codes.size()) {
      return Status::Invalid(
          "ArrowArray struct number of children incompatible with format string "
          "(mismatching number of union type codes) ",
          "'", c_struct_->format, "'");
    }
    for (const auto code : type_codes) {
      if (code < 0) {
        return Status::Invalid("Negative type code in union: format string '",
                               c_struct_->format, "'");
      }
    }
    if (mode == UnionMode::SPARSE) {
      type_ = sparse_union(std::move(fields), std::move(type_codes));
    } else {
      type_ = dense_union(std::move(fields), std::move(type_codes));
    }
    return Status::OK();
  }

  Status ProcessREE() {
    RETURN_NOT_OK(f_parser_.CheckAtEnd());