Struct CausalContext 

pub struct CausalContext { /* private fields */ }

Context linking an event to its causal predecessors.

Every agent-initiated event MUST include a CausalContext that:

• Links to the parent event that triggered this action
• Links to the root event (human request) that started the chain
• Identifies the session and principal

Invariants

• INV-CAUSAL-1: If parent_event_id is Some(p), then p.sequence < self.sequence
• INV-CAUSAL-2: root_event_id always points to an event with depth = 0
• INV-CAUSAL-3: depth <= session.max_depth
• INV-CAUSAL-4: Exactly one event per session has depth = 0

Implementations

impl CausalContext

pub fn builder() -> CausalContextBuilder

Create a builder for constructing a CausalContext.

pub fn root( event_id: EventId, session_id: SessionId, principal: PrincipalId, ) -> Self

Create a root context (depth 0) for a human-initiated event.

This is the starting point of any causal chain.

pub fn child(&self, parent_event_id: EventId, sequence: u64) -> Result<Self>

Create a child context from this context.

Arguments

• parent_event_id - The event ID of the parent (this context’s event)
• sequence - The sequence number for the new event (must be > self.sequence)

Errors

Returns error if sequence is not greater than parent’s sequence.

pub fn parent_event_id(&self) -> Option<&EventId>

Get the parent event ID.

pub fn root_event_id(&self) -> &EventId

Get the root event ID.

pub fn session_id(&self) -> SessionId

Get the session ID.

pub fn principal(&self) -> &PrincipalId

Get the principal.

pub fn depth(&self) -> u32

Get the depth in the causal chain.

pub fn sequence(&self) -> u64

Get the sequence number within the session.

pub fn cross_session_ref(&self) -> Option<&CrossSessionReference>

Get the cross-session reference, if any.

pub fn is_root(&self) -> bool

Check if this is a root event (depth = 0).

pub fn validate(&self, max_depth: u32) -> Result<()>

Validate this context against constraints.

Arguments

• max_depth - Maximum allowed depth (typically from session)

Errors

Returns error if validation fails.

pub fn validate_against_parent(&self, parent: &CausalContext) -> Result<()>

Validate this context against a parent context.

Ensures INV-CAUSAL-1 and INV-CAUSAL-2 hold.

Trait Implementations

impl Clone for CausalContext

fn clone(&self) -> CausalContext

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CausalContext

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CausalContext

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for CausalContext

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

Formats the value using the given formatter.

impl PartialEq for CausalContext

fn eq(&self, other: &CausalContext) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for CausalContext

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for CausalContext

impl StructuralPartialEq for CausalContext