Variables removed from class definition, but still referenced by code

> I have created a changeset in which a class is created with an iVar,  
> methods added that reference that iVar, and finally the class  
> definition is changed to remove the iVar.  Newly created instances of  
> the class behave as though the iVar is still present.
>
> Furthermore, when I add a new subclass that has an iVar of the same  
> name, the class compiles OK (if the superclass had explicitly defined  
> the iVar, I would not have been able to define it in the subclass).  
> However, different slots are being accessed by superclass methods and  
> subclass methods.  In the following code (file in the attached  
> changeset first):
>
> inst := ClassThatUsedToHaveAVariable new.
> inst add: 'string'.
> inst contents.
>
> subInst := ClassThatUsedToHaveAVariableSubclass new.
> subInst add: 'string2'.
> subInst subAdd: 'string3'.
> subInst contents.
> subInst subContents.
>
>
> 'subInst contents' and 'subInst subContents' do not give the same  
> result.  However, if the 'collection' variable is deleted from the  
> subclass definition, they do answer the same result.
>
> What exactly are the semantics here?  It seems like this could  possibly
> cause some problems.
>
> Thanks,
> Josh
>
>
>  
>  
>
>
> ------------------------------------------------------------------------
>
>

> When removing the variable from the superclass, "collection" got  
> transferred as a binding to Undeclared which makes it behave like a  
> class variable. Therefore, superclass and subclass have different  
> "meanings" when you refer to the name collection (superclass thinks  
> it's a "class var", subclass thinks it's an iVar).
>
> Cheers,
>   - Andreas
>
> Josh Gargus wrote:
>> I have created a changeset in which a class is created with an  
>> iVar,  methods added that reference that iVar, and finally the  
>> class  definition is changed to remove the iVar.  Newly created  
>> instances of  the class behave as though the iVar is still present.
>> Furthermore, when I add a new subclass that has an iVar of the  
>> same  name, the class compiles OK (if the superclass had  
>> explicitly defined  the iVar, I would not have been able to define  
>> it in the subclass).   However, different slots are being accessed  
>> by superclass methods and  subclass methods.  In the following  
>> code (file in the attached  changeset first):
>> inst := ClassThatUsedToHaveAVariable new.
>> inst add: 'string'.
>> inst contents.
>> subInst := ClassThatUsedToHaveAVariableSubclass new.
>> subInst add: 'string2'.
>> subInst subAdd: 'string3'.
>> subInst contents.
>> subInst subContents.
>> 'subInst contents' and 'subInst subContents' do not give the same  
>> result.  However, if the 'collection' variable is deleted from  
>> the  subclass definition, they do answer the same result.
>> What exactly are the semantics here?  It seems like this could  
>> possibly cause some problems.
>> Thanks,
>> Josh
>>    
>> ---------------------------------------------------------------------
>> ---
>
>