An enumeration of this package states itself two ways : the bare constant, when there is nothing more to say, and the member class, when there is — a status carrying the reason it was set. Stored and read back, the second form is a plain array, and turning it into the member class again is the same walk for every enumeration : hence one function rather than one per family.

The member is read from the payload in this order :

• additionalType, the URI every member states of itself since 1.5.0 — the same string the bare constant carries, so both forms filter alike ;
• @type, which carries the short name of the class (EventCancelled), never the URI — that is what the serialization writes, and what a payload written before additionalType existed carries alone.

⚠️ The two keys do not say the same thing, which is why both are read : a vocabulary is free to spell its URIs otherwise than its class names — AppointmentStatus spells …#NoShow where the class is AppointmentNoShow — so neither key can be derived from the other.

When nothing is recognized, $default is answered : the enumeration head itself, so an unknown status keeps the reason it carried rather than being dropped.