Re: Ada is getting more popular!

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Sun, 31 Oct 2010 11:54:22 +0100, Dmitry A. Kazakov  
<mailbox@dmitry-kazakov.de> a écrit:
> 5) you want to postpone some design decision/implementation to a later
> point. So you describe/implement what you know for certain right now, in
> the form of an abstract type, and let a derived type to define the rest
> when more information becomes available.
Makes me feel like the implementation language is used for modeling (this  
topic again).

I use to attempt that in the past (as I had a feeling for a need), with  
Pascal, but never felt satisfied. The implementation language is mostly  
not well suited for that, because it is intended to express things which  
works (even what is named “abstraction” in an implementation language,  
requires concrete interfaces). You have, not only to complete and fill the  
holes, but also have to change what was the prior abstraction (concrete  
interface again). Then, the prior abstraction is not readable anymore and  
is no more there to guide your steps as the concrete implementation goes.  
Finally, the abstraction is not recognizable at all, the completion of the  
implementation tries to follow something which is vanishing as it try to  
reach it (the abstraction) and goes erratic (more or less, will not say  
this produce a pure disaster). So I gave up with this, and tried another  
way : try to see the whole before starting any implementation (not the end  
of the story, as this is not more a piece of cake).

To be less formal and to talk about feeling, I also did not enjoyed  
incomplete implementations, which sooner or later had the taste of a  
pending failure (especially as time passed), this was driving me  
disappointed.

Now I make a wish : never start an implementation without a good model :)  
(a model which will stay there as the implementation goes). The place to  
write down one's first ideas is really the modal (I believe), not the  
source.

So I may add this one among the other things inheritance/derivation is not  
to be confused with : modeling (unless running Simula or SmallTalk, from  
which languages like Pascal and Ada are rather far away).


-- 
Si les chats miaulent et font autant de vocalises bizarres, c’est pas pour  
les chiens.