Ok I slept and now my brain is working. I think that having classTrait and trait together is important because else it would be the mess when you have a class method that uses an instance methods (both define in a trait). So conceptually this is one trait like in smalltalk you have one class and its metaclass.
The model is similar and to represent class trait we have a ClassTrait class. Stef On Jun 30, 2013, at 1:04 AM, Camillo Bruni <camillobr...@gmail.com> wrote: > so let's discuss that on monday with the trait specialists Damien et > Sebastian :) > > On 2013-06-29, at 23:34, Igor Stasenko <siguc...@gmail.com> wrote: >> yes, i don't know if it good or bad, but i'd rather prefer that traits >> applied to Behavior, >> but not to Class (which has two entangled behaviors). But maybe for >> human comprehension it is better.. >> but not for implementing, because it certainly makes model more complex. >> >> On 29 June 2013 22:52, Camillo Bruni <camillobr...@gmail.com> wrote: >>> >>> On 2013-06-29, at 22:32, Igor Stasenko <siguc...@gmail.com> wrote: >>> >>>> On 29 June 2013 21:21, Stéphane Ducasse <stephane.duca...@inria.fr> wrote: >>>>> >>>>> On Jun 29, 2013, at 8:19 PM, Igor Stasenko <siguc...@gmail.com> wrote: >>>>> >>>>>> On 29 June 2013 20:12, Camillo Bruni <camillobr...@gmail.com> wrote: >>>>>>> Working on the new class builder I have a hard time figuring out the >>>>>>> full trait >>>>>>> semantics. >>>>>>> >>>>>>> If I use a trait on instance side, does that imply that its classTrait >>>>>>> on the >>>>>>> metaclass? >>>>> >>>>> No. I do not think so (I will have to think). >>>>> Normally Trait and ClassTrait are two different classes. NOw I do not >>>>> remember if a trait is composed >>>>> of a classTrait too. >>>>> >>>> Trait has 'classTrait' >>> >>> yes, but the strange part is, that if you use a Trait on the instance-side >>> it >>> will automatically install the class trait as well. >>> >>> ClassDescription subclass: #Class >>> uses: TClass >>> ... >>> >>> and the users >>> >>> TClass users => an IdentitySet(Class) >>> TClass classTrait users => an IdentitySet(Class class) >>> >>> so in this case it implies that when you use a Trait on the instance side >>> it will >>> apply also it's classTrait to the class side. So is it ok then to enforce >>> that in >>> the new class builder? >>> >>> Currently you can do the following in the new class builder: >>> >>> PharoClassInstaller make: [:builder| >>> builder >>> superclass: Object; >>> name: 'Foo'; >>> traitComposition: TClass ] >>> >>> which will explicitely NOT install `TClass classTrait` in `Foo class`. >>> Does this behavior make sense? >> >> >> >> -- >> Best regards, >> Igor Stasenko. >> > >
