Re: Ada features

[Tucker Taft <stt@averstar.com>]

Bertrand Augereau wrote:
> 
> Hello,
> 
> I would like to know if there are standard solutions for those 2 things in
> Ada95 :
> 
> 1) Introspection

There is a new standard called "ASIS" which provides an API
for extracting information from the Ada program library.
However, this is not currently designed for use by a program
on "itself," though it might work if you run the program on
a machine where the program library is accessible at run-time.

> 2) The equivalence of what is done in Java by :
> class MVFramework
> 
>         class Model extends Object {...}
>         class View extends Object {...}
> }
> class MVSpreadsheetFramework extends MVFramework
> 
>         class Model {...} // Overrides class MVFramework.Model
>         class View {...}
> }
> 
> .i.e. overriding a nested class

This sort of "overriding" is really just "hiding".  There is
no run-time dispatching with this kind of overriding in Java (or
any other OOP that I know of).

In Ada, you might use child packages to accomplish something like this,
because the components of the enclosing package are visible within
the children, but you can hide them with components declared locally
within the child package. 

-- 
-Tucker Taft   stt@averstar.com   http://www.averstar.com/~stt/
Technical Director, Distributed IT Solutions  (www.averstar.com/tools)
AverStar (formerly Intermetrics, Inc.)   Burlington, MA  USA