Method DoAppend

cpp/src/arrow/compute/kernels/vector_hash.cc:303–332

  template <bool HasError = with_error_status>
  enable_if_t<!HasError, Status> DoAppend(const ArraySpan& arr) {
    return VisitArraySpanInline<Type>(
        arr,
        [this](Scalar v) {
          auto on_found = [this](int32_t memo_index) {
            action_.ObserveFound(memo_index);
          };
          auto on_not_found = [this](int32_t memo_index) {
            action_.ObserveNotFound(memo_index);
          };

          int32_t unused_memo_index;
          return memo_table_->GetOrInsert(v, std::move(on_found), std::move(on_not_found),
                                          &unused_memo_index);
        },
        [this]() {
          if (action_.ShouldEncodeNulls()) {
            auto on_found = [this](int32_t memo_index) {
              action_.ObserveNullFound(memo_index);
            };
            auto on_not_found = [this](int32_t memo_index) {
              action_.ObserveNullNotFound(memo_index);
            };
            memo_table_->GetOrInsertNull(std::move(on_found), std::move(on_not_found));
          } else {
            action_.ObserveNullNotFound(-1);
          }
          return Status::OK();
        });
  }

  template <bool HasError = with_error_status>
  enable_if_t<HasError, Status> DoAppend(const ArraySpan& arr) {