Re: Ada is getting more popular!

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

Le Fri, 29 Oct 2010 22:28:59 +0200, J-P. Rosen <rosen@adalog.fr> a écrit:
> Short answers:
> 1) Complexity of projects that use inheritance tends to grow quadratic
> 2) No other discipline of engineering uses classification as a /design/
> method; classification is used to organize artifacts after they have
> been designed
> 3) Not all people find classification natural. I don't know whether it
> is linked to left-brained or right-brained people, but there are huge
> variations among people.

May add classification is more static than composition, or at least,  
cannot evolve as easily as a construction built upon composition.

An example : the live beings are commonly subject to classification, but  
this is a flagrant case of distance with real life : live beings evolved  
such a way which make it impossible to be modeled with classification.  
Just think about the whales : first “amphibians” like all mammiformes,  
they later get legs to become animals living on the ground, then later  
again, loose their back legs to go back live to the aquatic world. A  
classification analysis would be broken all the time the story goes. And  
when will you decide their changed place in the classification ? This is a  
natural examples which show classification is not so much natural as one  
of the way to do OOD pretends.

I said classification may be good to handle large complex set of types (in  
reply to someone else), we may add this : classification may better suits  
well to what is static only (despite dynamic dispatching which is runtime  
only, the overall architecture is probably condemned to remain static).

A prediction to check would be that composition produce applications which  
are more easily updated and adapted to new specifications later after they  
were deployed (the corollary would be that in a similar case, a  
classification oriented designed application, would probably inspires the  
idea its better to re-start everything from the ground-up). To be checked…

-- 
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les chiens.