[self-interest] Transporter

[Thorsten Dittmar]

Hi Jecel,

you can not solve this problem by ordering, or let me say you can easily
construct a case in which ordering does not work anymore. I think it is a
real hard task to move objects from one system to another via plain text. I
remember me that back in the good old days Servio had a solution for that. I
was one of the goodies from their consulting group. I will try to find that
old media and will hope that it is still readable. If I will find something
useful I will send it to the list.

Do you use initializeTo: or don't you? When I remember me correctly, in
Smalltalk all the construction stuff (create classes and methods) will be
done first and all the initialize methods are called after that. I can try
to implement this, but when initializeTo: is just a relict from the old days
then it makes no sense to spend some effort.


On 6/6/02 5:44 PM, "Jecel Assumpcao Jr" <jecel at merlintec.com> wrote:

> On Wednesday 05 June 2002 15:03, Thorsten Dittmar wrote:
>> I'm not sure if I do some thing wrong or if it is a bug.
> 
> It is a bug.
> 
>> Here the situation:
>> I have a module with 2 prototypes (b and c).
>> Prototype b has a slot named x.
>> I use the annotation mechanism to initialize x as a copy of c.
>> So far so good... Now file out the module and use bootstrap read:
>> 'filename' From: 'dictionary' to file it in.
>> 
>> I will get an error because x can not be initialized because the
>> prototype c is not installed at all at this moment.
> 
> The problem is that the module created the objects in the wrong order.
> I tried this and got the same error as you did, and then I did it again
> but with the objects named "f" and "e" instead of "b" and "c" and it
> worked as it should.
> 
> If you look at the object "transporter fileOut slotSorter" (specially
> in the method 'topoSortFrom:Path:IfCycle:') you will see that though it
> starts out with a simple alphabetical order for the top slots in a
> module, it makes a great effort to find all dependencies and reorder
> things to fix them. Unfortunately it doesn't seem to handle this
> (rather common) case.
> 
>> Maybe I misused the annotation mechanism. Of course I know a
>> workaround, but I want to know what the right way for the not so
>> uncommon situation is.
> 
> One workaround is to choose top level names so things fileOut in the
> right order. To get back a module that would otherwise be lost you
> might want to edit the .self in a text editor, though this is a lot of
> work and the problem will reappear the next time you save the module.
> 
> I ran into this myself when working in tinySelf 1 back in 1997, which
> was one of the reasons I never finished debugging it. On the other
> hand, I wrote several other applications and my trainees did too and
> none of them had this problem. It depends on luck (what your objects
> are named) and style (whether you use "InitializeTo:" annotations or
> not).
> 
> -- Jecel
> 
> 
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