Method AppendArraySliceImpl

cpp/src/arrow/array/builder_dict.h:498–511

 protected:
  template <typename c_type>
  Status AppendArraySliceImpl(const typename TypeTraits<T>::ArrayType& dict,
                              const ArraySpan& array, int64_t offset, int64_t length) {
    const c_type* values = array.GetValues<c_type>(1) + offset;
    return VisitBitBlocks(
        array.buffers[0].data, array.offset + offset, length,
        [&](const int64_t position) {
          const int64_t index = static_cast<int64_t>(values[position]);
          if (dict.IsValid(index)) {
            return Append(dict.GetView(index));
          }
          return AppendNull();
        },
        [&]() { return AppendNull(); });
  }

  template <typename IndexType>
  Status AppendScalarImpl(const typename TypeTraits<T>::ArrayType& dict,