Struct SemanticPersonalizer 

pub struct SemanticPersonalizer {
    pub profiles: HashMap<u64, UserProfile>,
    pub decay_rate: f64,
}

Manages per-user interest profiles and applies personalization to search results.

Example

use ipfrs_semantic::personalizer::{
    InteractionRecord, InteractionType, SemanticPersonalizer,
};

let mut personalizer = SemanticPersonalizer::new(0.99);

personalizer.record_interaction(
    1,
    InteractionRecord {
        result_id: 42,
        interaction: InteractionType::Like,
        category: "rust".to_string(),
        timestamp_secs: 1_700_000_000,
    },
);

let results = vec![(42_u64, 0.8_f64, "rust".to_string())];
let biased = personalizer.apply_bias(1, &results);
assert!(!biased.is_empty());

Fields

profiles: HashMap<u64, UserProfile>

Map from user ID to that user’s interest profile.

decay_rate: f64

Multiplicative decay applied to existing category scores on each new interaction.

A value of 0.99 means each prior interaction contributes slightly less over time.

Implementations

impl SemanticPersonalizer

pub fn new(decay_rate: f64) -> Self

Create a new SemanticPersonalizer with the given decay rate.

decay_rate should be in (0.0, 1.0]. A typical value is 0.99.

pub fn record_interaction( &mut self, user_id: u64, interaction: InteractionRecord, )

Record a user interaction and update the corresponding interest profile.

Steps performed:

1. Upsert the user profile.
2. Apply decay to all existing category_scores.
3. Add the interaction weight to category_scores[category].
4. Update result_scores and synchronise liked_ids / disliked_ids.

pub fn compute_bias(&self, user_id: u64) -> Option<PersonalizationBias>

Compute personalization bias for a user.

Returns None if the user has no profile.

pub fn apply_bias( &self, user_id: u64, results: &[(u64, f64, String)], ) -> Vec<(u64, f64)>

Apply personalization bias to a slice of (result_id, score, category) tuples.

Each result’s score is multiplied by its category boost and its ID boost. Results are returned sorted by adjusted score descending.

If the user has no profile, results are returned sorted by the original scores.

pub fn profile(&self, user_id: u64) -> Option<&UserProfile>

Retrieve an immutable reference to a user’s profile.

pub fn stats(&self) -> (usize, u64)

Return aggregate statistics: (user_count, total_interactions).