AS3 enum example

gistfile1.txt

Enum base class:

 package language.extensions.enums
 {
   public class EnumBase
   {
     function EnumBase(token:*)
     {
       if (token !== runtimeInstantiationPreventionKey)
       {
         throw new Error("Cannot create new enums at runtime.");
       }
     }

     static protected function key():*
     {
       return runtimeInstantiationPreventionKey;
     }
   }
 }

 const runtimeInstantiationPreventionKey:* = {};


And a typical enum would be:

 package ...
 {
   public final class TrafficLights extends EnumBase
   {
     public static const Red:TrafficLights = new TrafficLights(key);
     public static const Amber:TrafficLights = new TrafficLights(key);
     public static const Green:TrafficLights = new TrafficLights(key);

     function TrafficLights(key:*)
     {
       super(key);
     }
   }
 }