Re: Your wish list for Ada 202X

["Randy Brukardt" <randy@rrsoftware.com>]

"J-P. Rosen" <rosen@adalog.fr> wrote in message 
news:lj8qid$j23$2@dont-email.me...
...
> I would tend to say that the "use" has the benefit to show you that you
> used the same name in various contexts with various meanings, and that a
> bit of reingeneering might be in order...

That's baloney. For instance, if we were to add an exception to Claw, it 
might very well have the same name as some exception the client (or even 
another third party) declared somewhere. Why do you think this is a problem? 
The teams maintaining the subsystems no contact and only happen to be both 
included in some client program. Our maintenance, however, could break the 
client program even though there is no intended use of the new entity. 
That's just wrong.

I've come to realize that the problem isn't use-clauses per-se, it's use 
clauses of things that maintenance can change (specifically when changes to 
non-overloadable entities can happen). As such, package use clause is 
acceptable on language-defined packages that don't allow 
implementation-defined identifiers, but that's it. In contrast, "use all 
type" (and the more limited "use type") are acceptable anywhere, as their 
maintenance hazard is much more limited, mostly to things for which having 
the same name and type profile is dubious anyway.

                                 Randy.