Re: Preventing type extensions

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

On Tue, 14 Sep 2010 21:08:16 +0300, Niklas Holsti wrote:

> Dmitry A. Kazakov wrote:
>> On Tue, 14 Sep 2010 15:16:37 +0300, Niklas Holsti wrote:
>> 
>>> If an operation of a parent type calls several other operations 
>>> with redispatching, and several derived types override these called
>>>  operations in diverse ways, perhaps you need to test the calling 
>>> operation separately for each derived class. But if I understand 
>>> Dmitry's standpoint correctly, he would avoid the redispatching by 
>>> overriding the calling operation for each derived class, giving the
>>> same total number of operations to be tested, right?
>> 
>> No, I am trying not to override non-abstract or non-null operations.
> 
> Aha! *Now* I understand your concept. In other words, you are trying to
> avoid all inheritance of behaviour and to allow only inheritance of
> interfaces and perhaps of structure (components).

No, I tend to override once. That is rather opposite to not inheriting.
Actually I have no problem with implementation inheritance.

Regarding interface inheritance I would gladly scrap ugly Ada 2005
interfaces and allow interface inheritance from any type and of course a
full MI.

>> I think you have a certain way of decomposition in mind. This
>> decomposition is driven by the idea of re-dispatch or OOTIA's "simple
>> dispatch" or, more generally, by object's identity (rather than
>> contract).
> 
> Possibly so. I have not knowingly modelled my design style on those 
> sources, but may have absorbed such ideas when I first learned about 
> object-oriented programming (and I no longer remember when that was).

It wasn't Ada 95, right? As for me, I somehow missed the tide of OO hype. I
just hated (and continue to hate) reading books on OO. I even didn't really
use OOP in C++ until Ada 95 came, so I learned both parallel, in
comparison.

>> I don't like this sort of decomposition in first place.
> 
> That is your right, and may you live long and prosper.

(:-))

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de