One thing to note is that accessors are required when using Traits.


On Jan 25, 2006, at 6:30 PM, Juan Vuletich wrote:

> I don't like general recipes on how to design and code. If  
> something "must always be done this way" then it's redundant. It  
> would be better to find a way for not needing to write it.
>
> If some time after you wrote a class (or a hierarchy), you need to  
> change the use of an instance variable to something else, you are  
> actually redesigning it. At that moment, you understand why  
> accessing that ivar directly was a bad idea, and you understand  
> your new needs. Therefore, that's a good time to think about the  
> meaning of that value, and find a better solution.
>
> Using accessors from the begining, "just in case", means losing the  
> oportunity to think about what you really need, and express that  
> cleanly in the code.
>
> I don't think you need an excuse for not using accessors. I think  
> you need a reason to actually use them. Most instance variables do  
> not need accessors and they shouldn't exist.
>
> BTW, if a class (or hierachy) needs to "hide" something from  
> itself, maybe it'ss a sign that it's getting too big, and it could  
> be broken in components.
>
> Anyway, coding in Smalltalk is a lot about aesthetics and not that  
> much about rational arguments. So it's ok to have different taste.
>
> Cheers,
> Juan
> ----- Original Message ----- From: "Hilaire Fernandes"  
> <hilaire at ext.cri74.org>
> To: "The general-purpose Squeak developers list" <squeak- 
> dev at lists.squeakfoundation.org>
> Sent: Wednesday, January 25, 2006 4:44 AM
> Subject: Re: Evilness object oriented approach in Morph
>
>
>> Look like we have two antagonist paradigms: one for reusability  
>> (which is at the heart of OOP) and the other one to protect access  
>> to attributes (which is also at the heart of OOP).
>>
>> Given the nature of Smalltalk, code reusability, I like to think  
>> the 1st paradigm is more important.
>>
>> But beside that, there are no "rational" excuse to not use  
>> accessors instead of direct attribute access; otherwise why  
>> defining the accessors? For decoration?
>>
>> Hilaire
>>
>>
>> Juan Vuletich a écrit :
>>> Hi Hilaire,
>>> Yes, refactoring Morphic code is something to be considered.
>>> But I'm not a believer of the so called "double encapsulation".  
>>> If a class has an accessor methods, it allows anyone to know (and  
>>> enven change!) the value of the instance variable. That is  
>>> against encapsulation. It is the object (via its class) who  
>>> defines what it makes public and what it keeps private. If a  
>>> subclass needs to change that, it's a good time for refactoring.
>>> Cheers,
>>> Juan Vuletich
>>> ----- Original Message ----- From: "Hilaire Fernandes"  
>>> <hilaire at ext.cri74.org>
>>> To: "Squeak Devel" <squeak-dev at lists.squeakfoundation.org>
>>> Sent: Sunday, January 22, 2006 8:21 AM
>>> Subject: Evilness object oriented approach in Morph
>>>
>>>
>>>> I have realized that many of the Morph method does not use instance
>>>> variable accessor but direct access to the instance variable.
>>>> One may think this improve the efficiency of the method but in  
>>>> the other
>>>> hand its downgrade (or just break) the oriented object  
>>>> efficiency of
>>>> thus objets.
>>>> Is refactoring the code of the Moprh methods something to be  
>>>> considered?
>>>>
>>>> Hilaire
>>>>
>>>>
>>>>
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>>>
>>>
>>
>>
>> -- 
>> ADD R0,R1,R2,LSL #2
>>
>>
>>
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>
>