Re: Constructing an object

[Jean-Pierre Rosen <rosen@adalog.fr>]

Randy Brukardt a �crit :
> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
>>They aren't extensible in the sense that you can only override or inherit.
>>It is too dangerous for constructors and assignments. BTW, Ada does not to
>>completely override them anyway. For example the parts responsible for
>>initialization of the components cannot be overridden. One cannot have a
>>task component which will not start because Initialize does not call the
>>parent's one! (:-))
> 
> 
> Ah, I see. Certainly you are right here. I see that a lot in Finalize
> routines; it is real easy to forget to call the Finalize for the parent
> type. There ought to be a better way of extending rather than replacing
> routines; that's especially true since requires an explicit type conversion
> to the parent to make that call, and it is easy to get wrong (and go
> infinitely recursive).
> 
I think CLOS has such a feature, but it raises an issue:
sometimes you want to call the parent Finalize *before* your own 
Finalize, sometimes *after*. If it is automatic, you must force one of 
them, which makes problems if you want the other one.

-- 
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            J-P. Rosen (rosen@adalog.fr)
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