Function VisitSequenceMasked

python/pyarrow/src/arrow/python/iterators.h:108–170

/// Visit sequence with null mask
template <class VisitorFunc>
inline Status VisitSequenceMasked(PyObject* obj, PyObject* mo, int64_t offset,
                                  VisitorFunc&& func) {
  if (has_numpy() && PyArray_Check(mo)) {
    PyArrayObject* mask = reinterpret_cast<PyArrayObject*>(mo);
    if (PyArray_NDIM(mask) != 1) {
      return Status::Invalid("Mask must be 1D array");
    }
    if (PyArray_SIZE(mask) != static_cast<int64_t>(PySequence_Size(obj))) {
      return Status::Invalid("Mask was a different length from sequence being converted");
    }

    const int dtype = fix_numpy_type_num(PyArray_DESCR(mask)->type_num);
    if (dtype == NPY_BOOL) {
      Ndarray1DIndexer<uint8_t> mask_values(mask);

      return VisitSequenceGeneric(
          obj, offset,
          [&func, &mask_values](PyObject* value, int64_t i, bool* keep_going) {
            return func(value, mask_values[i], keep_going);
          });
    } else {
      return Status::TypeError("Mask must be boolean dtype");
    }
  } else if (py::is_array(mo)) {
    auto unwrap_mask_result = unwrap_array(mo);
    ARROW_RETURN_NOT_OK(unwrap_mask_result);
    std::shared_ptr<Array> mask_ = unwrap_mask_result.ValueOrDie();
    if (mask_->type_id() != Type::type::BOOL) {
      return Status::TypeError("Mask must be an array of booleans");
    }

    if (mask_->length() != PySequence_Size(obj)) {
      return Status::Invalid("Mask was a different length from sequence being converted");
    }

    if (mask_->null_count() != 0) {
      return Status::TypeError("Mask must be an array of booleans");
    }

    BooleanArray* boolmask = checked_cast<BooleanArray*>(mask_.get());
    return VisitSequenceGeneric(
        obj, offset, [&func, &boolmask](PyObject* value, int64_t i, bool* keep_going) {
          return func(value, boolmask->Value(i), keep_going);
        });
  } else if (PySequence_Check(mo)) {
    if (PySequence_Size(mo) != PySequence_Size(obj)) {
      return Status::Invalid("Mask was a different length from sequence being converted");
    }
    RETURN_IF_PYERROR();

    return VisitSequenceGeneric(
        obj, offset, [&func, &mo](PyObject* value, int64_t i, bool* keep_going) {
          OwnedRef value_ref(PySequence_ITEM(mo, i));
          if (!PyBool_Check(value_ref.obj()))
            return Status::TypeError("Mask must be a sequence of booleans");
          return func(value, value_ref.obj() == Py_True, keep_going);
        });
  } else {