oxibrain-index 0.6.0

Lexical and graph index primitives for oxibrain — n-gram, TF-IDF, adjacency, community
Documentation 
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//! In-memory kNN index. Brute-force cosine similarity for M2 (deterministic).
use crate::vector::{TfIdfVector, cosine_sim};
pub struct KnnIndex {
    entries: Vec<(String, TfIdfVector)>,
}
impl KnnIndex {
    pub fn new() -> Self {
        Self {
            entries: Vec::new(),
        }
    }
    pub fn insert(&mut self, id: String, v: TfIdfVector) {
        self.entries.push((id, v));
    }
    pub fn search(&self, q: &TfIdfVector, k: usize) -> Vec<(String, f64)> {
        let mut s: Vec<(String, f64)> = self
            .entries
            .iter()
            .map(|(id, v)| (id.clone(), cosine_sim(q, v)))
            .collect();
        s.sort_by(|a, b| {
            b.1.partial_cmp(&a.1)
                .unwrap_or(std::cmp::Ordering::Equal)
                .then_with(|| a.0.cmp(&b.0))
        });
        s.truncate(k);
        s
    }
    pub fn len(&self) -> usize {
        self.entries.len()
    }
    pub fn is_empty(&self) -> bool {
        self.entries.is_empty()
    }
}
impl Default for KnnIndex {
    fn default() -> Self {
        Self::new()
    }
}