portIndex property

Stable ordering index among ports in the parent occurrence.

Set by the adapter that creates the signal. For ports (signals with a direction), this records the deterministic position from the original source (netlist JSON iteration order, ROHD module port declaration order, etc.). Internal signals have null.

HierarchyOccurrence.buildAddresses places ports before internal signals when assigning OccurrenceAddress indices, so a port with portIndex == k will receive signal address index k.

Consumers that store connectivity by (nodeId, portIndex) tuples (e.g. schematic hyperedges) rely on this value remaining stable across incremental hierarchy expansion.