Enum Condition 

pub enum Condition<S> {
    Always,
    Never,
    OnSkip,
    OnError,
    Named(NamedConditionId),
    And(Vec<Condition<S>>),
    Or(Vec<Condition<S>>),
    Not(Box<Condition<S>>),
    Custom {
        label: String,
        f: ConditionFn<S>,
    },
}

A declarative predicate deciding whether an edge fires.

The engine evaluates a completed node’s outgoing edges in declaration order; every edge whose condition matches fires (emits an activation token). Write mutually exclusive conditions for branch selection — e.g. an is_done / not_done named pair — and prefer an Condition::Always fallback so a node can never strand into a dead-end.

The S parameter appears only in the Condition::Custom escape hatch; the serializable subset is entirely S-free (see crate::def::ConditionDef).

Variants

Always

Always fires when the source completes successfully (the dataflow-profile default).

Never

Never fires. Useful to park an edge in a saved graph without deleting it.

OnSkip

Fires when the source execution carried a BspSkip marker (dataflow profile).

OnError

Fires when the source node failed and its recovery policy is crate::recovery::RecoveryPolicy::RouteToErrorEdge. Error paths become visible, GUI-renderable topology instead of implicit aborts.

Named(NamedConditionId)

Consumer-registered named predicate over &S + value store.

And(Vec<Condition<S>>)

Ordered short-circuit conjunction over conditions.

Or(Vec<Condition<S>>)

Ordered short-circuit disjunction over conditions.

Not(Box<Condition<S>>)

Negation of a condition.

Custom

Escape hatch for the long tail. Never serializes its closure: the definition layer keeps only label, and instantiation fails closed unless a condition with that label is re-registered. The GUI renders it as an opaque gray box. Use sparingly.

Fields

label: String

Human-readable label shown in the GUI and used as the re-registration key.

f: ConditionFn<S>

The predicate over consumer state and value store.

Implementations

impl<S> Condition<S>

pub fn eval(&self, ctx: &ConditionEval<'_, S>) -> bool

Evaluates the condition in the given context.

A missing Condition::Named registration evaluates to false; graph validation (crate::engine::BspEngine::validate_with_report / BspGraph::from_def) reports unknown names loudly before a run ever starts.

pub fn label(&self) -> String

A short human-readable label for interceptor events and GUI badges.

pub fn collect_named(&self, out: &mut Vec<String>)

Collects every named-condition reference in this condition tree.

Used by validation to check registry completeness.

pub fn collect_custom_labels(&self, out: &mut Vec<String>)

Collects the labels of every Condition::Custom leaf in this condition tree.

Custom closures do not serialize; definitions carrying them fail closed at instantiation unless the label is registered as a named condition.

Trait Implementations

impl<S> Clone for Condition<S>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<S> Debug for Condition<S>

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

Formats the value using the given formatter.