Re: Subclassing EnumSet to add an interface?

Eric Smith <eric@brouhaha.com> writes:


As others have pointed out, EnumSet cannot be subclassed.

Two approaches spring to mind, if all you need are keys based on
sets of enum values:

Make an adapter key object containing the EnumSet:

  class MyDictionaryKey<T extends Enum>
    implements Comparable<MyDictionaryKey<T>> {
      private final EnumSet<T> enumSet;
      public MyDictionaryKey(EnumSet<T> enumSet) {
        this.enumSet = enumSet;
      }
      public EnumSet<T> getEnumSet() {
        return enumSet;
      }
      public int compareTo(MyDictionaryKey<T> other) {
        /// ...your impl
      }
  }

and use it for keys in your dictionary.

Or, create a Comparator<EnumSet<MyEnum>> and use a dictionary
that allows a comparator for the keys.

/L
--
Lasse Reichstein Nielsen - lrn@hotpop.com
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