[Newbies] UndefinedObject

Bert Freudenberg bert at impara.de
Tue Jun 13 06:45:21 UTC 2006


Am 12.06.2006 um 23:51 schrieb mathieu:

> Bert Freudenberg a écrit :
>>
>> Am 12.06.2006 um 23:08 schrieb nicolas cellier:
>>
>>> Le Dimanche 11 Juin 2006 14:54, mathieu a écrit :
>>>> An other things intresting is where do nil being initialized? [I  
>>>> know he
>>>> is an old friend but it should have been born in a certain  
>>>> time  :-) ]
>>>>
>>>
>>> I think this one is so essential, that you can only find it in some
>>> bootstrap
>>> method not written in Smalltalk.
>>>
>>> There must be a few initializer that you will hardly find in the
>>> image, like
>>> initialization of Smalltalk (I mean SystemDictionary).
>>> Did you see something like Smalltalk at: #Smalltalk put: Smalltalk ?
>>>
>>> Like the (Metaclass class class) knot...
>>>
>>> Like the Process stuff...
>>>
>>> Feel free to discover more!
>>>
>>> You must admit that an image must have been created once ex  
>>> nihilo (or
>>> rather
>>> ex C-code glue).
>>
>> Most certainly not C. The first Smalltalk prototype was a BASIC  
>> program,
>> Smalltalk-72 was coded in assembly. We'd have to ask Dan to be sure
>> where the nil instance in Squeak comes from ...
>>
>> - Bert -
>>
>
> Yes like an historian job. :-)

The ultimate historic reference is Alan Kay's "The Early History of  
Smalltalk" in "History of Programming Languages HOPL-II", which you  
can find in a scientific library near you. Or print this scanned  
version (it's hard to read on screen):

http://www.smalltalk.org/downloads/papers/SmalltalkHistoryHOPL.pdf

(there are HTML versions of this on the net, but they all have  
transcription errors AFAIK)

Also, Dwight Hughes has collected several papers about Smalltalk  
history:

	http://www.ipa.net/~dwighth/

And, to understand the life at PARC, where Smalltalk was born, I very  
much like "Dealers of Lightning" by Hiltzik. An enlightening read :)

> Very instresting. :-)
>
> But who where the first object Metacalss or Behavior? :-)

I'd guess Object was the first behavior. Metaclasses where only  
introduced much much later, in Smalltalk-80, and many agree they are  
an unnecessary complication.

- Bert -



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