Hmm, got it wrong, it should read (basicNew: AND initialize:) OR super new:

Le jeu. 5 sept. 2019 à 00:40, Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com> a écrit :

> To be absolutely thorough, also consider how the new: message is
> associated to basicNew:  or super new: and initialize: for variable
> subclasses - or eventually just initialize: for those quaking like a
> variable subclass...
>
> Le jeu. 5 sept. 2019 à 00:27, Thiede, Christoph <
> Christoph.Thiede at student.hpi.uni-potsdam.de> a écrit :
>
>> Okay, thank you for the really comprehensive clarification :)
>>
>>
>> I was already aware of the "basic" meaning of #basicNew, but I also met a
>> pattern that told me to only use super to call the same-named base method.
>> It feels like breaking with the law of encapsulation when you can
>> always refer to the base version of a method that has been explicitly
>> changed in the current class.
>>
>>
>> But I guess in this case, it is more important to deal with possible
>> logic that could be introduced in (Proto)Object>>#initialize.
>>
>>
>> Christoph
>> ------------------------------
>> *Von:* Squeak-dev <squeak-dev-bounces at lists.squeakfoundation.org> im
>> Auftrag von tim Rowledge <tim at rowledge.org>
>> *Gesendet:* Mittwoch, 4. September 2019 23:43:22
>> *An:* The general-purpose Squeak developers list
>> *Betreff:* Re: [squeak-dev] The Trunk: Collections-mt.851.mcz
>>
>> Well, to try to explain this mostly to Christoph, #basicNew should do
>> only the primitive creation of the chunk of object memory, hence the
>> 'basic' (and that does include some hacks for certain classes
>> likeBoxedFloat etc).
>> #new and other initial creation methods can do further things, like
>> setting initial values of some instance variables, registering external
>> resources, etc.
>>
>> So they do not in general work equivalently, deliberately. At the most
>> basic level, #new sends #basicNew to create the memory and then #initialize
>> to do the ... initialisation. If that initialize does stuff your specific
>> needs would prefer to avoid, use #basicNew and your own initialisation
>> sequence.
>>
>> As an example, consider WriteStream>on:from:to: which uses `self
>> basicNew`. It could use #new without any difference in effect because there
>> is no implementation of #initialize for WriteStreams until you get to the
>> null version in ProtoObject.
>>
>> In contrast, imagine a class where the normal use needs a load of
>> instance variable to be set up just so, but you have a need for a quite
>> different setup and it would waste a lot of cycles to do the typical init
>> and then overwrite almost all of it. That might justify a separate creation
>> method that uses #basicNew and a specialised init method.
>>
>> There's also the question of self vs super in your original question.
>> Remember, super is for case where you need to skip up the class tree
>> starting in the superclass of *the class in which the method you are
>> running* lives. This is *not* always the super class of the object
>> executing the method. Lots of people get this wrong.
>>
>> There are good explanations of the real effects of this crucial point in
>> the Blue Book etc and you really need an example class tree with at least 4
>> level and it's too long to type here. Suffice to say that the practical
>> difference between `self basicNew` and `super new` can be significant.
>>
>> > On 2019-09-04, at 2:07 PM, Nicolas Cellier <
>> nicolas.cellier.aka.nice at gmail.com> wrote:
>> >
>> > Hmm, I just starred at method 'source with it' in a SpurVMMaker image
>> and got
>> > - 252 hits for 'self basicNew';
>> > - 109 hits for 'super new'.
>> >
>> > So it might depend on context... This would deserve more statistics
>> (age of method, initials, whether new is raising an Error or not, whether
>> instance side initialize does nothing or the wrong thing, etc...)
>> >
>> > Le mer. 4 sept. 2019 à 22:38, tim Rowledge <tim at rowledge.org> a écrit :
>> >
>> >
>> > > On 2019-09-04, at 12:58 PM, Thiede, Christoph <
>> Christoph.Thiede at student.hpi.uni-potsdam.de> wrote:
>> > >
>> > > Thank you :)
>> > >
>> > > A very minor question: Would you favor [self basicNew] over [super
>> new]? It will work completely equivalently, but what is the better style?
>> >
>> > ^super new
>> >
>> > `self basicNew` will not always work equivalently. And I can almost
>> guarantee it will always do the wrong thing just when you feel sure it is
>> doing the right thing. And you will suffer Debugging Hell.
>> >
>> >
>> > tim
>> > --
>> > tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
>> > Why use one word when two polysyllabic agglomerates will do?
>> >
>> >
>> >
>> >
>> >
>> >
>>
>>
>> tim
>> --
>> tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
>> Computing Dictionary: LOOP: (go to LOOP)
>>
>>
>>
>>
>>
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