clone vs shallowCopy

Now it would be nice to clean that because in VW you have copy, shallowCopy and postCopy and it works.
They removed veryDeepCopy and other friends even when they were at the time were they could burn engineering time
on that.

So for me clone is one too many.
And worse cloning and object cannot be a shallowCopy semantics. it should be more a veryDeepInnerVeryCopy (I could not resist sorry)
Of course we already clean and remove the veryDeepInnerCopy.... No comment.

>>> - #copy is the normal copy operation. It should be used by default and
>>> never overridden. It calls #postCopy that can be overridden to have
>>> class specific copy semantics.
>>>
>>> - #shallowCopy does a shallow copy. It should never be overridden and
>>> only be used if you want to get these very specific semantics.
>>>
>>> - #deepCopy does a deep copy. It should never be overridden and only
>>> be used if you want to get these very specific semantics.
>>>
>>> - #clone comes from eToys and Morphic (AFAIK). It implements some
>>> other copy semantics than #copy. I don't think that anybody should
>>> call this method, other than code that depends on this particular copy
>>> behavior.
>>
>> we should copy that in Object class comment and all the methods
>>
>>
>> where do you see that it is morphic related for me clone is only implemented
>> on character, Boolean, Object, SMalltInt symbol, UndefinedObject
>
> Back in the old days, Squeak 1.1 didn't have primitive 148 (which is now used by both #shallowCopy and #clone). #shallowCopy was the way to create a "one-level copy" of an Object. It had the same code as today, but with no primitive.
> Primitive 148 was introduced somewhere between 1.1 and 1.19 (note that 1.2 came after 1.19). 1.19 (and probably earlier versions, but not 1.1) had #clone which was primitive only and #shallowCopy which didn't use the primitive. Morphic was being ported to Squeak at the time and it was the only user of #clone. Morphs were copied by #clone which was pretty fast, while other objects used #shallowCopy. Later the use of #clone started to spread, until primitive 148 was added to #shallowCopy. Sends of #clone were replaced with #shallowCopy and #copy, but #clone was kept, probably for backwards compatibility.

>
> #clone and #shallowCopy have a difference in their semantics. If the vm cannot allocate enough space for the new object, #clone raises an error immediately, while #shallowCopy signals the low space semaphore, so the image or the user can do something, then retries the copying.
>
>

> Levente
>
>>
>>>
>>> This is exactly the same problematic as with #=. There can't be just
>>> one #=. Other clients might consider other things when comparing
>>> objects.

>>>
>>> Lukas
>>>
>>> --
>>> Lukas Renggli
>>> http://www.lukas-renggli.ch
>>>
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>>
>>
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