Trait ChildOccurrenceProduct

Source

pub trait ChildOccurrenceProduct<Shape>: BirthNodewhere
    Shape: ChildOccurrenceShape,{
    type Product;
}

Expand description

Sealed occurrence product of a closed direct-child birth node.

The product starts at ChildHead and advances through ChildTail<Position> in exactly the same way as DispatchBirth and ChildPosition. A downstream runtime selects only the result shape through ChildOccurrenceShape; it cannot reclassify a foreign type as a birth node or replace the recursion.

This product is intentionally direct rather than transitive. Each installed actor owns the bindings for its own Behavior::Birth; when a concrete child is installed, the same product law applies to that child’s birth algebra.

Foreign types cannot extend the closed node algebra:

struct RuntimeShape;
impl behavior::ChildOccurrenceShape for RuntimeShape {
    type Empty = ();
}
impl<Occurrence, Child: behavior::Behavior, Tail>
    behavior::ChildOccurrenceMember<Occurrence, Child, Tail> for RuntimeShape
{
    type Member = ();
}

struct ForeignNode;
impl behavior::ChildOccurrenceProduct<RuntimeShape> for ForeignNode {
    type Product = ();
}