Frankly I found strange that we care about this because
we can still instantiate an abstract class
and I do not really see how annotating that a class is abstract help
us.
If I can instantiate an object and send messages and the class is
abstract but there is no
usage of abstract messages who cares?
May be I do not have such scenarios.
Stef
> On 31 Mar 2019, at 22:30, Norbert Hartl <[email protected]> wrote:
>
>
>
> Am 30.03.2019 um 21:05 schrieb Denis Kudriashov <[email protected]
> <mailto:[email protected]>>:
>
>> We can also look into it from the other side. All these methods are
>> definitely a kind of code duplication.
>> I think what we need here is an explicit property for classes. It could be
>> even part of class definition.
>
> I use it myself but it always feels a bit strange. On the one hand a class is
> abstract if it includes something like subclassResponsibility and on the
> other hand we try to make it some kind of type. If it would be the latter one
> you could make that a Trait. Feels even more strange but ....
>
> Norbert
>> BTW do we plan new class definition in Pharo 8?
>>
>> сб, 30 мар. 2019 г. в 18:35, Denis Kudriashov <[email protected]
>> <mailto:[email protected]>>:
>> Hello.
>>
>> We did recently several cleanups by marking abstract classes as abstract
>> using #isAbstract method (https://github.com/pharo-project/pharo/pull/3087
>> <https://github.com/pharo-project/pharo/pull/3087>,
>> https://github.com/pharo-ide/Calypso/pull/462
>> <https://github.com/pharo-ide/Calypso/pull/462>) .
>>
>> I would like to discuss here and decide what the right way to implement this
>> method.
>>
>> The logic behind is to only return true when receiver is defining class of
>> this method. And it should be false for any subclasses (if they do not
>> implement own #isAbstract method).
>>
>> There is old pattern for implementation to compare name of class:
>>
>> MyAbstractClass class>>isAbstract
>> ^self name == #MyAbstractClass
>>
>> It is used in many places (mostly tests). And it was used in recent Pharo PR
>> (3087).
>>
>> We have another pattern in other places which simply compare self with class:
>>
>> MyAbstractClass class>>isAbstract
>> ^self == MyAbstractClass
>>
>> And in Calypso I used "more simplified" version using equality:
>>
>> MyAbstractClass class>>isAbstract
>> ^self = MyAbstractClass
>>
>> I think we would all agree that simplest version is last one. It does not
>> raise any question about why we compare name or why we use identity
>> comparison. So this is my choice in this discussion.
>>
>> Please write arguments about your preferred implementation. And let's choose
>> single way at the end. There is an idea to add a command into browser to
>> make classes abstract. And this decision will be used as a template.
>>
>> Best regards,
>> Denis
>>
