Getting item from column

column.cc

int column_bool_at(void *vp, long long i) {
  auto column = (Column *)vp;
	// TODO: errors
  if (column == nullptr) {
    return -1;
  }

  if (column->ptr->type()->id() != BOOL_DTYPE) {
    return -1;
  }

  if ((i < 0) || (i >= column->ptr->length())) {
      return -1;
  }

  auto chunks = column->ptr->data();
  int index = i;

	for (int c = 0; c < chunks->num_chunks(); c++) {
		auto chunk = chunks->chunk(c);
		if (index < chunk->length()) {
			return chunk->data[index];
		}
		index -= chunk->length();
	}
}