Re: What would you like in Ada202X?

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

Le Thu, 26 Apr 2012 00:33:11 +0200, Jeffrey Carter  
<spam.jrcarter.not@spam.not.acm.org> a écrit:

> On 04/25/2012 02:30 PM, Yannick Duchêne (Hibou57) wrote:
>>
>> And you have to modify and respecify the package each time you want to  
>> extend
>> it? The child package way is more modular.
>
> Ada emphasizes ease of reading over ease of writing (this is and always  
> has been an explicit design goal stated at the beginning of the ARM);  
> programming by extension (and your comment) emphasizes ease of writing  
> over ease of reading. This is why I've always objected to including  
> programming-by-extension features in Ada.

Child package are not less readable, as all kind of modularity ease  
understanding, be it either child packages or nested packages. However,  
there is another less mentioned — while as much important — requirement of  
Ada, which is project and source management (thus the “is separate”). And  
child packages ease project management, for the reason I gave. Also, child  
packages allows for optional additions or various alternatives for a given  
addition, by means of project configuration: just remove the path to a set  
of child packages source and specs, to remove it from a project. With  
nested package, you have to modify the package each time.

Getting ride of child packages (as back to Ada 83), would promise  
nightmares for many ones.

-- 
“Syntactic sugar causes cancer of the semi-colons.” [1]
“Structured Programming supports the law of the excluded muddle.” [1]
[1]: Epigrams on Programming — Alan J. — P. Yale University