Function calculate_distances 

pub fn calculate_distances(
    embeddings: &Array2<f32>,
    q: &Array1<f32>,
    metric: &Metric,
    is_normalized: bool,
) -> Result<Array1<f32>>

Scores every row of embeddings against the query q, as L2 distances or, for IP, inner products. Set is_normalized only if every row is unit-length, which lets L2 skip computing the rows’ norms. L2 distance for unit-length rows = sqrt(1 − 2·e·q + ‖q‖²).