Re: Standard Ada Preprocessor

["Robert I. Eachus" <rieachus@comcast.net>]

Robert A Duff wrote:

> I'm rather skeptical of talk about "Ada philosophy".  I agree with you
> and MDC that the issue is a very practical one.  It's all well and good
> to recommend encapsulating system dependencies in package bodies and so
> forth.  But you still need some mechanism to select which body to use in
> each case.  I don't see any advantage to using make-file hackery for
> that, over using #ifdef's.

I completely and totally agree.  One of the things I love about Ada is 
the ability to avoid messing around with makefiles.

But this again totally misses what I keep saying about Ada 
pre-processors.  I don't avoid them intentionally.  It is just that if I 
get to the body of one of these implementation dependent packages, I 
usually write it using ifs and case statements planning to convert to 
#ifdefs later if needed.

This allows me to use one Ada compiler to (compile-time) debug the Ada 
code completely.  But once it compiles cleanly I don't switch to 
pre-processor directives for the fun of it.  I wait until I need it. 
I'm still waiting...

If your experience is different, fine.  But why are we arguing?  I never 
said that Ada compilers shouldn't support pre-processors, or that they 
shouldn't be used.  I just suggested waiting until it is needed.

I'm going to get back to work on some Ada code I hope to post soon. 
Again, if it needs a pre-processor to make it portable, I'll use one. 
But I don't expect it to happen.

Now if you think there should be a STANDARD Ada pre-processor, that is 
fine with me as well.  Just don't expect the ARG to develop the 
standard, form a PRG or whatever instead.  The ARG already has enough to do.

>>I am not against any of these techniques. What I am against
>>is the notion that "no, we don't do it that way because it
>>might get abused".

Definitely not my position.  I am the typical engineer.  I work very 
hard at being lazy.  So I will use whatever tools make my life easier. 
In this case, my "ivory tower notion" is that if I can do it in Ada, or 
with a pre-processor, I'll do it in Ada, even if it takes a little more 
design effort up front.  I know that when I am deep into schedule 
pressure and design changes I will thank myself.


-- 
                                           Robert I. Eachus

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