----- Original Message -----
> From: "Brian Goetz" <brian.go...@oracle.com>
> To: "Tagir Valeev" <amae...@gmail.com>
> Cc: "Remi Forax" <fo...@univ-mlv.fr>, "Zheka Kozlov" <orionllm...@gmail.com>,
> "amber-spec-experts"
> <amber-spec-experts@openjdk.java.net>
> Sent: Vendredi 24 Septembre 2021 18:55:01
> Subject: Re: Sealed Exception
> I agree that this was just something we overlooked, though not necessarily
> with
> the leap from there to “so of course we should fix it”; the incremental
> return-on-complexity there is probably quite low, unless the spec fix is truly
> trivial. As Tagir points out, this is at least currently something quite
> rare.
Not fixing interaction between features in a language, here exception and
sealed classes has a cost in term of how people make their mind around a
feature.
Having a non consistent story for a feature make people less inclined to use it.
Given that sealed classes is something pivotal to the introduction of pattern
matching, i think we should cover the last mile in this case.
BTW, i don't thing we are very good at the moment at explaining where and why
pattern matching should be used.
Rémi
>
>> On Sep 24, 2021, at 7:40 AM, Tagir Valeev <amae...@gmail.com> wrote:
>>
>> Agreed. Looks like this case was just overlooked. Abstract exception class
>> is quite an unusual thing but probably it will be more useful with sealed
>> classes.
>>
>> With best regards,
>> Tagir Valeev.
>>
>> On Fri, Sep 24, 2021 at 4:45 PM Remi Forax <fo...@univ-mlv.fr> wrote:
>>
>>> ----- Original Message -----
>>>> From: "Zheka Kozlov" <orionllm...@gmail.com>
>>>> To: "amber-dev" <amber-...@openjdk.java.net>
>>>> Sent: Vendredi 24 Septembre 2021 10:30:54
>>>> Subject: Sealed Exception
>>>
>>>> Hi!
>>>
>>> CC amber-spec-experts
>>>
>>>>
>>>> Java 17 compiler forces me to insert an unreachable catch block for the
>>>> base Exception:
>>>>
>>>> public static void main(String[] args) {
>>>> try {
>>>> f();
>>>> } catch (Ex1 e) {
>>>> e.printStackTrace();
>>>> } catch (Ex2 e) {
>>>> e.printStackTrace();
>>>> } catch (BaseEx e) {
>>>> // Unreachable
>>>> }
>>>> }
>>>>
>>>> private static void f() throws BaseEx {
>>>> }
>>>>
>>>> sealed abstract class BaseEx extends Exception permits Ex1, Ex2 {
>>>> }
>>>>
>>>> Otherwise it doesn't compile. Was this decision intentional?
>>>
>>> I don't think so, it's something we have overlooked.
>>>
>>>> If yes, why? If not, can we fix it? I see this as an unfortunate
>>> limitation.
>>>
>>> I agree, it should be fixed.
>>>
>>>>
>>>> With best regards, Zheka Kozlov.
>>>
>>> Regards,
>>> Rémi
>>>
