While I agree with all comments in this thread so far, I have one additional
comment relating to the type parameter.
Since the set of permitted classes must be subclasses of T, should the
declaration be:
public Class<? extends T>[] getPermittedSubclasses() { .. }
-Chris.
> On 26 Oct 2020, at 14:15, Vicente Romero <[email protected]> wrote:
>
> Hi Remi,
>
> I will update the name, adding the `get` back,
>
> Thanks,
> Vicente
>
> On 10/24/20 6:32 PM, [email protected] wrote:
>> Hi Vicente,
>>
>> the 'get' was removed because the method was not returning Class objects,
>> now that permittedSubclasses behave like the other methods of
>> java.lang.Class,
>> the name should be changed back to "get..." to reflect that.
>>
>> Rémi
>>
>> De: "Vicente Romero" <[email protected]>
>> À: "Remi Forax" <[email protected]>, "Brian Goetz" <[email protected]>,
>> "Gavin Bierman" <[email protected]>
>> Cc: "amber-spec-experts" <[email protected]>, "joe darcy"
>> <[email protected]>
>> Envoyé: Samedi 24 Octobre 2020 23:40:58
>> Objet: Re: getPermittedSubclasses() on j.l.rClass returning an array of
>> ClassDesc
>> Hi,
>>
>> The name of the method is still: permittedSubclasses
>>
>> Vicente
>>
>> On 10/24/20 7:35 AM, [email protected] wrote:
>> Ok nice,
>> I suppose permittedSubclasses has been renamed to getPermittedSubclasses at
>> the same time.
>>
>> Rémi
>>
>> De: "Brian Goetz" <[email protected]>
>> À: "Gavin Bierman" <[email protected]>, "Remi Forax"
>> <[email protected]>
>> Cc: "amber-spec-experts" <[email protected]>, "joe darcy"
>> <[email protected]>
>> Envoyé: Vendredi 23 Octobre 2020 17:36:44
>> Objet: Re: getPermittedSubclasses() on j.l.rClass returning an array of
>> ClassDesc
>> FTR: this was largely a "for consistency" decision, because nestmates does
>> it the same way. (Which is to say, it was a deliberate suboptimal choice
>> aimed at minimizing the number of API idioms that users of reflection had to
>> deal with.)
>>
>> On 10/23/2020 11:27 AM, Gavin Bierman wrote:
>> Just to follow this up; we have decided to change the signature of
>> permittedSubclasses to the following:
>>
>> public Class<?>[] permittedSubclasses() {}
>>
>> Thanks!
>> Gavin
>>
>>
>> On 8 May 2020, at 23:53, Remi Forax <[email protected]>
>> wrote:
>>
>> The current draft of the reflection API for the sealed keyword adds a method
>> getPermittedSubclasses() [1] to java.lang.Class.
>>
>> I'm not fully sure that returning an array of ClassDesc is the right choice
>> here, mainly for two reasons,
>>
>> 1/ it's weird to return an array of ClassDesc when all others similar
>> methods return an array of Class,
>> I know why a ClassDesc might be "better" because it avoid the class
>> loading,
>> but it also means that now to fully understand java.lang.Class, people has
>> to understand how java.lang.constant works.
>> The java.lang.constant API was not designed for that, the first line of
>> the overview of this package talks about descriptors, constant pool and
>> indy, not something beginners should worry about.
>>
>> 2/ returning a symbolic view (ClassDesc) instead of a Class is *very* error
>> prone from a user POV, to resolve a ClassDesc to a class, the user as to
>> provide a Lookup
>> and there is a good chance that users will pick the wrong ones. The number
>> of people that understand classloading and how Lookup works is < 10,
>> even experts struggle given the number of time the Lookup API as to be
>> patched in recent years. Returning a ClassDesc in this context is like
>> asking a child
>> to read the serial number of a loaded gun.
>> Perhaps a way to mitigate that is to provide the code a user should use to
>> get the equivalent classes in the javadoc of getPermittedSubclasses().
>>
>> cheers,
>> Rémi
>>
>> [1]
>> https://bugs.openjdk.java.net/browse/JDK-8244556
>>
>>
>>
>>
>
