Struct Association 

pub struct Association {
    pub source: Uuid,
    pub target: Uuid,
    pub association_type: String,
    pub weight: f32,
    pub created_at: DateTime<Utc>,
    pub link_type: LinkType,
    pub co_activation_count: u32,
    pub last_activated_at: DateTime<Utc>,
    pub decay_half_life_days: f32,
}

An association between two memories.

Fields

source: Uuid

Source memory UUID

target: Uuid

Target memory UUID

association_type: String

Legacy association type string (auto-populated from link_type)

weight: f32

Weight / strength (0.0 to 1.0) — dynamic, Hebbian

created_at: DateTime<Utc>

Creation timestamp

link_type: LinkType

Typed link kind

co_activation_count: u32

Number of co-activations (Hebbian counter)

last_activated_at: DateTime<Utc>

Last time this link was activated (for decay computation)

decay_half_life_days: f32

Decay half-life in days for the link weight

Implementations

impl Association

pub fn new(source: Uuid, target: Uuid, link_type: LinkType, weight: f32) -> Self

Create a new typed association.

pub const fn with_half_life_days(self, days: f32) -> Self

Create a new association with a custom decay half-life.

pub fn activate(&mut self)

Hebbian co-activation — strengthens the link weight.

Boosts weight by 0.1 * (1.0 - current_weight) (diminishing returns), increments co_activation_count, and updates last_activated_at.

pub fn decay(&mut self, now: DateTime<Utc>)

Apply exponential decay to link weight based on time since last activation.

weight *= 0.5 ^ (days_since_activation / decay_half_life_days)

pub fn should_prune(&self, threshold: f32) -> bool

Whether this link has decayed below a pruning threshold.

pub fn encode_key(&self) -> Vec<u8>

Encode the composite key: source(16) + target(16) = 32 bytes.

pub fn encode_key_pair(source: Uuid, target: Uuid) -> Vec<u8>

Encode a key from source and target UUIDs.

Trait Implementations

impl Clone for Association

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Association

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Association

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Association

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

where __S: Serializer,

Serialize this value into the given Serde serializer.