Enum LeafOutcome 

pub enum LeafOutcome {
    True,
    False,
    Unknown,
}

Three-valued (SQL Kleene) outcome of evaluating a single leaf predicate against one row.

Unknown is produced when the predicate references a column that is absent from the row or whose value is Null — i.e. a SQL NULL operand. Callers that only need pure-AND rejection (the historical evaluate_predicates) treat Unknown and False identically; callers that evaluate OR/NOT (the Flight nested-predicate evaluator, issue #834) must distinguish them to match SQL WHERE semantics.

Variants

True

The predicate is definitely satisfied.

False

The predicate is definitely not satisfied.

Unknown

The predicate’s column is missing or NULL (SQL UNKNOWN).

Trait Implementations

impl Clone for LeafOutcome

fn clone(&self) -> LeafOutcome

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for LeafOutcome

impl Debug for LeafOutcome

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

Formats the value using the given formatter.

impl Eq for LeafOutcome

impl PartialEq for LeafOutcome

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for LeafOutcome