Eliot Miranda a écrit :
> 
> 
> On Mon, Oct 13, 2008 at 2:02 AM, Martin Beck 
> <martin.beck at hpi.uni-potsdam.de <mailto:martin.beck at hpi.uni-potsdam.de>> 
> wrote:
> 
>     Craig Latta wrote:
>      >
>      > Hi Stef--
>      >
>      >> To my stupefaction I discovered that the classVariables of a
>     class are
>      >> not the same as the ones of its metaclass.
>      >>
>      >> TheRoot classVarNames ~= TheRoot class classVarNames
>      >>
>      >> Does any body have some ideas why this is like that? For me this
>     is a
>      >> conceptual bug.
>      >
>      >      Actually, metaclasses don't really have class variables at all.
>      > Class variables are defined by Class, which is a sibling of
>     Metaclass,
>      > not a superclass. There's a method in Behavior which just answers
>     a new
>      > empty Set for classVarNames; this is what you're invoking when you
>      > evaluate [TheRoot class classVarNames].
>      >
>     However,
> 
>     TheRoot classPool = TheRoot class classPool
> 
>     evaluates to true...
> 
>     Regards,
>     Martin
> 
> 
> One fix is to add the following method:
> ------------8<-----------
> !Metaclass methodsFor: 'class variables' stamp: 'eem 10/13/2008 12:37'!
> classVarNames
> "Answer a Set of the names of the class variables defined in the 
> receiver's instance."
> 
> ^thisClass classVarNames! !
> ------------8<-----------
> c.f. Metaclass>>classPool.
> 
> But a better fix is to move Class>>classVarNames to ClassDescription:
> ------------8<-----------
> 'From Croquet1.0beta of 11 April 2006 [latest update: #1] on 13 October 
> 2008 at 12:41:36 pm'!
> 
> !ClassDescription methodsFor: 'class variables' stamp: 'eem 10/13/2008 
> 12:41'!
> classVarNames
> "Answer a Set of the names of the class variables defined in the receiver."
> 
> ^self classPool keys! !
> 
> Class removeSelector: #classVarNames!
> ------------8<-----------
> 
> Whoever said that the class variables of a metaclass should be those of 
> Metaclass is very wrong.  Code compiled in  the context of a metaclass 
> includes the class variables of the non-metaclass (metaclass's 
> instance), otherwise one couldn't access class variables in class-side 
> methods.
> 
> 
> ------------------------------------------------------------------------
> 
> 

It is funny with Object because:

     (Object class allSuperclasses includes: Object).

So the Object classPool keys will be accessible twice (It does not seem 
to hurt).

Nicolas