Re: Standard Ada Preprocessor

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

"Warren W. Gay VE3WWG" <warren@ve3wwg.tk> wrote in message
news:e9gRb.4112$qU3.177385@news20.bellglobal.com...
> Jeffrey Carter wrote:
>
> > Warren W. Gay VE3WWG wrote:
> >
> >> Matrix 10 POSIX environments x 10 versions of the same, x 4
> >> different versions of a curses library. That leaves you with
> >> 400 different custom (possibly groups of) packages to work
> >> with. Real slick indeed. :(
> >
> > One standard POSIX-Ada binding
>
> Impossible. Some UNIces provide some API structure members,
> while others don't, or provide something else again. Yes,
> you can dumb it down to a "standard" (or omit non-universal
> functionality), but by doing so you throw away functionality.
> I find that unacceptable.

What is the point of having that functionality? Any code depending on it is
by definition not portable. If you can't abstract a reasonable facimile of
it, it probably isn't worth using. Otherwise, it will poison your whole
application, and lock it to a few targets.

What Claw does for features that aren't available on the current target is
to raise Not_Supported_Error (which hopefully the caller can do something
useful with, such as fall back to something that is supported). Thus, the
interface is as rich as possible. That probably won't work everywhere, but
if you want portability, you have to eliminate functionality that is
available only a few targets. (Which is why embedded code pretty much cannot
be portable by definition.)

               Randy.