Method null_count

cpp/src/arrow/compute/exec.h:314–320

XXX: here temporarily for compatibility with datum, see e.g. MakeStructExec in scalar_nested.cc

  /// XXX: here temporarily for compatibility with datum, see
  /// e.g. MakeStructExec in scalar_nested.cc
  int64_t null_count() const {
    if (this->is_array()) {
      return this->array.GetNullCount();
    } else {
      return this->scalar->is_valid ? 0 : 1;
    }
  }

  const DataType* type() const {
    if (this->is_array()) {