Enum Distance 

#[non_exhaustive]
pub enum Distance {
    Euclidean,
    Cosine,
    DotProduct,
}

A distance / similarity metric over f32 vectors.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Euclidean

L2 distance: sqrt(sum((a_i - b_i)^2)).

Cosine

1 - cos(theta), where cos(theta) = (a . b) / (|a| |b|). Returns 0 for identical direction, 2 for opposite.

DotProduct

Negated dot product: -(a . b). The negation makes the metric monotonically smaller-is-closer so a single comparator works across all three.

Implementations

impl Distance

pub fn score(self, a: &[f32], b: &[f32]) -> f32

Score a against b. Smaller scores mean closer.

Panics

Does not panic. Mismatched lengths return f32::INFINITY to signal “incomparable” without bringing the search down; production callers should validate dimensions upstream of this routine.

pub fn name(self) -> &'static str

Human-readable name suitable for logging or JSON serialisation.

Trait Implementations

impl Clone for Distance

fn clone(&self) -> Distance

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Distance

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Distance

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Distance

fn eq(&self, other: &Distance) -> 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 Serialize for Distance

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for Distance

impl Eq for Distance

impl StructuralPartialEq for Distance