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From: Mike Amling on 2 May 2010 15:48
www wrote:
> I have three enums:
>
> enum MyEnum
> {
> A, B, C, D
> }
>
> enum HisEnum
> {
> A, B, C, D, M, N
> }
>
> enum HerEnum
> {
> A, B, C, D, P
> }
>
> A, B, C, and D shows up three times in three enums. I am wondering if
> the code can be improved to avoid such repeated coding. Ideally, I would
> think MyEnum can be the "parent class" of HisEnum and HerEnum. But enum
> cannot sublclass.

You could get something that looks like what you're looking for with

enum Omnus {
A, B, M, N, P;
XYZ whatever() {
...
}
}

class HisEnum {
static HisEnum A=new HisEnum(Omnus.A);
static HisEnum B=new HisEnum(Omnus.B);
static HisEnum M=new HisEnum(Omnus.M);
static HisEnum N=new HisEnum(Omnus.N);

private final Omnus mine;
HisEnum(Omnus which) {
mine=which;
}

XYZ whatever() {
return mine.whatever();
}
}

class HerEnum {
static HisEnum A=new HisEnum(Omnus.A);
static HisEnum B=new HisEnum(Omnus.B);
static HisEnum P=new HisEnum(Omnus.P);

private final Omnus mine;

HerEnum(Omnus which) {
mine=which;
}

XYZ whatever() {
return mine.whatever();
}
}

This allows you to code HisEnum.N but not HisEnum.P. It allows you to
declare a parameter, variable or return type to be HerEnum that can only
be A, B or P, but not M or N, which I assume is what you want. And
HisEnum.B.whatever() has the same value as HerEnum.B.whatever() and
Omnus.B.whatever().

--Mike Amling
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