Soliciting opinions on JDK-8219412

[Maurizio Cimadamore]

Yes, you are correct. The underlying bootstrap is already capable to 
handle enum constants:

https://download.java.net/java/early_access/jdk20/docs/api/java.base/java/lang/runtime/SwitchBootstraps.html#enumSwitch(java.lang.invoke.MethodHandles.Lookup,java.lang.String,java.lang.invoke.MethodType,java.lang.Object...)

I also agree that the right time to make the refactoring is when 
patterns in switch is finalized (as SwitchBootstraps is a preview class).

Cheers
Maurizio

On 10/01/2023 18:44, Archie Cobbs wrote:
> Following up on this...
>
> It looks to me like this is pretty much implemented already as part of 
> the JEP 433 "Pattern Matching for switch" preview feature.
>
> It appears that TransPatterns.handleSwitch() would DTRT. Currently 
> it's only used if the switch has one or more patterns, but since it's 
> written to handle switches with a combination of patterns and 
> constants, simply feeding it a "traditional" enum switch should 
> accomplish what we want.
>
> So that makes this primarily a refactoring task, but one that should 
> probably wait until JEP 433 is out of preview.
>
> -Archie
>
> On Mon, Jan 9, 2023 at 10:20 AM Archie Cobbs <archie.cobbs at gmail.com> 
> wrote:
>
>     Thanks for the comments. Using invokedynamic makes perfect sense!
>     (and I'm disappointed I didn't think of it :)
>
>     I'll take a look into it and report back.
>
>     -Archie
>
>     On Mon, Jan 9, 2023 at 9:54 AM Maurizio Cimadamore
>     <maurizio.cimadamore at oracle.com> wrote:
>
>         I agree with Brian. If we want to fix this and put our hands
>         in the enum switch classification, I think the best use of our
>         time would be to tweak enum switches to adopt the superior
>         indy-based classification approach, which should be immune to
>         the issue you present.
>
>         Thanks
>         Maurizio
>
>         On 09/01/2023 15:35, Brian Goetz wrote:
>>         Another strategy is to use an `invokedynamic` as a switch
>>         classifier.  (I believe there is even a bootstrap for this
>>         implemented somewhere.)
>
>
>     -- 
>     Archie L. Cobbs
>
>
>
> -- 
> Archie L. Cobbs
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