Re: ifdef replacement for GNAT

[kilgallen@eisner.decus.org (Larry Kilgallen)]

In article <6gn4q1$ee6@drn.newsguy.com>, nabbasi@earthlink.net writes:

> I think the hardest thing is to foresee in advanced what the platform
> specific calls will be. or what the platform specific components will be.
> 
> for example reading a directory file I do not think is available on windows
> as is done on UNIX. and so this have to be wrapped (or abstracted).

This does not seem so hard to me if you start with multiple operating
systems not particularly related to each other (i.e., not all Unix, not
all Windows, etc.).  After you have found the operations which differ
among Solaris X86 (always pick the smaller subset), MicroVMS (yes, it
had Ada), Windows 3.1, OS/2 and MVS, you have minimized your future work
in discovering new areas which are uncomon.

The worst thing is to start with one operating system and presume that
all others are like it.  Windows programmers and Unix programmers seem
to be most prone to this pattern; the rest of us know from the start that
we are in a minority :-).

Larry Kilgallen