Enum SubscribeOutcome 

pub enum SubscribeOutcome {
    Live,
    Deferred,
    Dead {
        node: NodeId,
    },
}

Outcome of ProducerCtx::subscribe_to — the producer-layer translation of graphrefly_core::SubscribeError into a positive outcome enum that operators (zip / concat / race / take_until / merge_map / switch_map / exhaust_map / concat_map) can match on for per-operator dead-source semantics.

Introduced /qa F2 (2026-05-10) to close the silent-wedge class of bugs where operators previously couldn’t tell that a subscribe_to call had been rejected per R2.2.7.b (non-resubscribable terminal source) — pre-F2 the rejection was logged-and-skipped silently, which left zip waiting for a queue that would never fill, concat stuck on a source that would never advance, etc.

Mirrors the per-domain status-string-union pattern used in TS (RefineStatus, AgentStatus, process status: "running" | "completed" | "errored" | "cancelled") — each operator-layer outcome lives in its own typed enum rather than sharing a global Outcome<T, E> type.

Variants

Live

Subscription installed successfully. The ProducerNodeState holds the [Subscription]; no further operator action required.

Deferred

Subscription was deferred to wave-end via the graphrefly_core::DeferredProducerOp::Callback queue (Phase H+ STRICT, D115). The deferred callback installs the subscription after wave_guards release. Operators MAY treat this as Live for lifecycle bookkeeping — the subscription WILL be installed; just not yet.

Dead

The target node is non-resubscribable AND has terminated (R2.2.7.b, D118). The sink will NOT be installed. Operators MUST handle this per their semantics:

• zip / take_until (source): self-Complete (tuple stream can never form; take_until’s source is gone).
• concat: advance to the next source (treat as inner Complete signal).
• race: mark completed[idx] = true; if all sources are Dead/Complete, self-Complete.
• take_until (notifier): ignore (notifier signal will never fire; take_until reduces to a passthrough of source).
• switch_map / exhaust_map / concat_map / merge_map (inner): treat as immediate on_inner_complete — decrement active, advance to next, check self-Complete trigger.

Fields

node: NodeId

The dead node that rejected the subscribe.

Trait Implementations

impl Clone for SubscribeOutcome

fn clone(&self) -> SubscribeOutcome

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SubscribeOutcome

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

Formats the value using the given formatter.

impl PartialEq for SubscribeOutcome

fn eq(&self, other: &SubscribeOutcome) -> 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 Copy for SubscribeOutcome

impl Eq for SubscribeOutcome

impl StructuralPartialEq for SubscribeOutcome