Enum NullHandling 

pub enum NullHandling {
    Drop,
    Preserve,
    PreserveAndExpandEmpty,
}

How UnnestOptions handles NULL and empty list values in the input column.

The variants enumerate the three observable behaviors so that callers do not have to compose multiple boolean flags to express what they want.

Variants

Drop

Drop rows where the input list is NULL or empty. Matches the default behavior of systems such as DuckDB and ClickHouse.

Preserve

Preserve NULL input rows as a single output row containing NULL. Empty lists still produce zero output rows. This is the default and matches DataFusion’s historical preserve_nulls = true behavior.

PreserveAndExpandEmpty

Like Self::Preserve, and additionally treat an empty list identically to a NULL list, producing a single output row containing NULL.

Trait Implementations

impl Clone for NullHandling

fn clone(&self) -> NullHandling

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for NullHandling

impl Debug for NullHandling

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for NullHandling

fn default() -> NullHandling

Returns the “default value” for a type.

impl Eq for NullHandling

impl Hash for NullHandling

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for NullHandling

fn eq(&self, other: &NullHandling) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for NullHandling

fn partial_cmp(&self, other: &NullHandling) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for NullHandling