Struct FoldContext 

pub struct FoldContext {
    pub as_of: DateTime<Utc>,
    pub correlation_id: Option<Uuid>,
    pub extra: SharedJson,
}

Context for fold operations.

The context parameterizes fold behavior — same entries with different contexts may produce different derived states.

as_of defaults to the Unix epoch (DateTime::<Utc>::default()). Callers that need “now” must pass it explicitly via FoldContext::at. This preserves the ADR-024 “no clock” invariant for the foundation layer.

Fields

as_of: DateTime<Utc>

Point in time to evaluate (for temporal queries)

correlation_id: Option<Uuid>

Correlation ID for tracing

extra: SharedJson

Additional context as shared JSON.

Uses SharedJson (Arc-backed) so clones are cheap in hot paths.

Implementations

impl FoldContext

pub fn new() -> Self

Create a new context with the Unix epoch as as_of.

Per ADR-024 (“no clock”), the foundation layer does not call Utc::now(). Pass an explicit timestamp via FoldContext::at when a real wall-clock instant is needed.

pub fn at(as_of: DateTime<Utc>) -> Self

Create a context for a specific point in time.

pub fn with_correlation_id(self, id: Uuid) -> Self

Set the correlation ID.

pub fn with_extra(self, extra: impl Into<SharedJson>) -> Self

Set extra context.

pub fn extra(&self) -> &Value

Borrow the extra context as a plain serde_json::Value.

pub fn extra_mut(&mut self) -> &mut Value

Mutably access the extra context, cloning the shared payload only if needed.

Trait Implementations

impl Clone for FoldContext

fn clone(&self) -> FoldContext

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FoldContext

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

Formats the value using the given formatter.

impl Default for FoldContext

fn default() -> FoldContext

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for FoldContext

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for FoldContext

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

where __S: Serializer,

Serialize this value into the given Serde serializer.