Sealed local interfaces

[Vicente Romero]

Hi Remi,

On 8/17/20 10:07 AM, Remi Forax wrote:
> I've found a discrepancies in the current spec of sealed,
> the current spec allows local sealed interface but you have no way to provide a sub-types apart a sealed sub interfaces.
>
> A record or an interface is allowed to be declared inside a method,
> by example, this is a valid code
>    static void foo() {
>      interface I {}
>
>      record Foo() implements I {}
>    }
>
> the interface can also be sealed
>    static void foo() {
>      sealed interface I {}
>
>      record Foo implements I {}
>    }
>
> but this code does not compile because Foo is a local class and a local class can not implement a sealed interface.
>
> This rule was intended to not allow this kind of code
>    sealed interface I {}
>    
>    static void foo() {
>      record Foo implements I {}
>    }
> because the interface I is visible while Foo is not.
>
> But we have forgotten to discuss about the case where both Foo and I are in the same scope.
>
> I see two possible fixes
> - disallow sealed local interfaces
+1 having a local sealed class seems like unnecessary, this option makes 
more sense to me
> - allow local class/record to implement a sealed interface if they are in the same scope.
>
> Rémi
Vicente