Enum RecallPolicy 

pub enum RecallPolicy {
    Importance,
    Hybrid {
        recency_weight: f32,
        frequency_weight: f32,
    },
}

Controls how memories are scored and ranked during recall.

Interaction with DecayPolicy

When both a DecayPolicy and a RecallPolicy are configured, decay is applied before scoring. This means that for RecallPolicy::Importance, an old high-importance memory may rank lower than a fresh low-importance memory after decay has reduced its score.

For RecallPolicy::Hybrid, the recency_weight term already captures temporal distance; combining it with a DecayPolicy therefore applies a double time penalty — set one or the other, not both, unless the double penalty is intentional.

Score Calculation Example

Given two memories, each with importance = 0.5:

• Memory A: recall_count = 0, inserted 1 hour ago
• Memory B: recall_count = 10, inserted 10 hours ago

With recency_weight = 1.0 and frequency_weight = 0.1:

• Score A = 0.5 + 1.0 × 1.0 + 0.1 × 0 = 1.5 (recency wins)
• Score B = 0.5 + 1.0 × (−10.0) + 0.1 × 10 = −8.5 (old → ranked lower)

Note: the recency term uses negative hours-since-creation so older items score lower.

Variants

Importance

Rank purely by importance score (default).

Hybrid

Hybrid score: blends importance, recency, and recall frequency.

score = importance + recency_score * recency_weight + frequency_score * frequency_weight where recency_score = exp(-age_hours / 24.0) and frequency_score = recall_count / (max_recall_count + 1) (normalized).

Fields

recency_weight: f32

Weight applied to the recency component of the hybrid score.

frequency_weight: f32

Weight applied to the recall-frequency component of the hybrid score.

Trait Implementations

impl Clone for RecallPolicy

fn clone(&self) -> RecallPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RecallPolicy

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

Formats the value using the given formatter.

impl Default for RecallPolicy

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for RecallPolicy

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for RecallPolicy

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

where __S: Serializer,

Serialize this value into the given Serde serializer.