Re: AIs for Ada extensions

[aek@vib.usr.pu.ru (Alexander Kopilovitch)]

Robert I. Eachus wrote:

> > It seems to be an unfortunate collision that multiple new packages should be
> > proposed when Abstract Interfaces still aren't established firmly.
> > It is highly likely that some packages (for example, Data structures
> > components) may look significantly better if they can use Abstract Interfaces.
>
>I personally don't see any conflict.  The interface AI will allow easier 
>bindings to C++ and Java.  But in Ada, mix-ins are a better abstraction 
>IMHO for containers.  The advantage is that you can easily put objects 
>in a container even if the original declarer of the type/class had no 
>idea that they would be put in a container.  For example:
>...

Yes, but what about similar containers, such as various flavors of List?
And it is not an easy task to align properly the above your words with another
your opinion (with which I fully agree), posted here about 3 weeks ago -
I mean the following:

>Date: Thu, 29 May 2003 02:22:22 GMT
>Subject: Re: Problem space and solution space
>
>...  In Ada you tend not to have one sort
>package in your toolbox, or one list type implementation, you have
>several.  Now the programmer solving some problem sees a part of his
>decomposition that can be solved by a list package or a sort package,
>and does a generic instantiation.  The problem is that there is no easy
>way, in Ada, to express a binding to a member of the class of sort
>generics, but to delay the choice of the actual mapping.
>
>This is why one of the features I expect interfaces to add to Ada is a
>better way of organizing collections of sort algorithms and the like.


Alexander Kopilovitch                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia