Re: Q: Endless loop by dispatching

[Dmitry A. Kazakov <mailbox@dmitry-kazakov.de>]

On Tue, 15 Jul 2003 12:23:29 -0500, "Randy Brukardt"
<randy@rrsoftware.com> wrote:

>"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message
>news:h5c7hvgol0sscrnaj98qp071903m9hoh5c@4ax.com...
>> Probably it is worth to think how to eliminate any need in Y'Parent?
>> For example one could provide some sort of overriding by extension.
>> I.e. the bodies which would implicitly call the overriden body, as it
>> is manually made in Initialize/Finalize.
>
>Interesting idea, but you'd need some way to specify when the overridden
>body is called. For instance, you usually call the overridden body first for
>Initialize (so the parent components are Initialized before you do anything)
>and last for Finalize (so the parent components still exist while you are
>writing your code). I've even had a few cases where I had to do it in the
>middle (with operations before an after it).

One should invent a good syntax suggar for this. Which is rather
difficult. There are actually two things in it:

1. There should be a way to declare some primitive operation saying
that it cannot be overriden completely. One might wish it for things
like Initialize/Finalize. Then probably there should be a way to say
where an override is allowed to add something.

2. During overriding one should specifiy where the override(s) places
the extension. I think that it should be specified in the body, while
the specification should only say that it gets overridden.

The question is syntax and a good balance between 1. and 2., i.e
between contract and implementation. The most complicated cases would
emerge from things like Adjust, I suppose.

It is also related to an ability to explicitly specify that a
subroutine is an overriding, not overloading, to avoid undesired
overloading in case ot typo errors. I do not know whether there is an
AI on that. If yes, they should be considered together.

---
Regards,
Dmitry Kazakov
www.dmitry-kazakov.de