def boundary
import bendvy-ecs-core@0.1.0.4/internal/relation_failures/domains.bend as Domainsimport Base
import bendvy-ecs-core@0.1.0.4/event_runtime.bend as Ev
33def boundary(positions: List<&2,Ev.Position>,+ids: List<&2,U32>,acc: Nat) -> Nat:
34 match positions:
35 case []: acc
36 case Ev.Position{id,cursor,_} <> rest: boundary(rest,ids,select_boundary(member(ids,id),cursor,acc))