Yes, it is always worth it venturing in these barren lands with lots of  
uncharted territory :-)

On Wednesday, Nov 5, 2003, at 22:24 Europe/Zurich, Sam Adams wrote:

>
>
>
>
> Thanks for the reminder Stef.
> If my prodded memory still serves, I think Ralph Johnson did document  
> the
> implementation trick in TypeObject.
> What I really wanted to focus on was the alternate metaclass universe
> ideas.  Our particular Metaclass substrate forces us into certain
> categories of design and implementation approaches.  Other substrates  
> would
> enforce other approaches.  Just wondering if there is something there  
> worth
> investigating.  For instance, would our beloved design patterns still  
> apply
> in these alternate universes?  Some clearly do, others may not.  The  
> same
> may be said of new patterns to be discovered in these alt spaces, they  
> may
> be useful in ours as well.
>
> Regards,
> Sam
>
>
>
> Sam S. Adams, IBM Distinguished Engineer, IBM Research
> tie line 444-0736, outside 919-254-0736, email: ssadams at us.ibm.com
> <<Hebrews 11:6, Proverbs 3:5-6, Romans 1:16-17, I Corinthians 1:10>>
>
>
>
> |---------+--------------------------------------------->
> |         |           ducasse <ducasse at iam.unibe.ch>    |
> |         |           Sent by:                          |
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> |         |           ndation.org                       |
> |         |                                             |
> |         |                                             |
> |         |           11/05/2003 03:42 PM               |
> |         |           Please respond to The             |
> |         |           general-purpose Squeak developers |
> |         |           list                              |
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>   |       cc:                                                           
>                          |
>   |       Subject:  Re: About reflection and it engineering             
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>                          |
>> ---------------------------------------------------------------------- 
>> -----------------------|
>
>
>
>
> hi adam
>
> did you read the TypeObject pattern because it is interesting too and
> somehow related?
> You have one class that represents the type VideoTape then a class
> representing the actual physical
> instance that has a reference to its type VideoTape.
>
> For plant collector like me, you can see that when you want to model
> plant, the physical plant
> in described by a class that coers its actual state and specificity
> while the TypeClass covers the generic aspect such as the
> classifications and other business that fanatic collector really enjoy.
> Stef
>
>
> On Mercredi, nov 5, 2003, at 21:21 Europe/Zurich, Sam Adams wrote:
>
>> To be more direct, you create a class (say AccountType) in Squeak  
>> whose
>> instances are different types of accounts, and then create a class  
>> (say
>> Account) in Squeak whose instances are the individual accounts
>> themselves,
>> but act as if they were instances of the instances of AccountType.   
>> The
>> AccountType instances would define the structure(data) and
>> behavior(policies, notifications, etc) for the Account instances.   
>> Each
>> Account instance would upon creation refer to its AccountType "class"
>> for
>> details of what kind of private data structure (variables) to
>> construct.
>> During later execution, the Account instance would refer to its
>> AccountType
>> "class" for its behavior, which would be shared across all Acount
>> instances
>> referencing the same AccountType "class".
>
>
>
>
>
>
Roel Wuyts                                                               
   DeComp
roel.wuyts at ulb.ac.be                               Université Libre de  
Bruxelles
http://homepages.ulb.ac.be/~rowuyts/                                     
Belgique
Board Member of the European Smalltalk User Group: www.esug.org