Re: Standard Ada Preprocessor (Was: why ada is so unpopular ?)

["Warren W. Gay VE3WWG" <warren@ve3wwg.tk>]

Marin David Condic wrote:
> Preben Randhol wrote:
>> Well, who would be in charge of an Ada GUI and develop it actively and
>> not every 10-15 years ?
...
> Ada has this "Portability Fetish" that often cripples it. "If we can't 
> make a feature work on everything from a PC to a digital toaster then it 
> can't be part of the language!" We solve that with some kind of library 
> external to the standard that exists in source and works on some stated 
> number of platforms and where it doesn't work - don't try to use it. The 
> problem, of course, is to get the vendors to actually think that Ada 
> *needs* something like this and exhibit the will & leadership to get it.
...
> MDC

Portability of course is an important issue. This becomes even more
important to Open Sourced projects, since they must be easy to
compile and maintain for all/most flavours of UNIX, and different
Windows environments (native and/or CYGWIN etc.)

(I'll probably take some heat for this but..)

In my opinion, the preprocessing of C code has made C the clear
winner (and now C++) for portability. Examples of code that
compiles and runs on the ancient Atari, BeOS, UNIX and Windows
etc are not hard to find. Unless the Ada code is pretty
much disconnected from the operating system, you won't find
the same level of portability.

Granted preprocessing results in ugly code. But it is
pretty clear that developers prefer to maintain one
source module, rather than trying to keep 10+ parallel modules
synchronized (for each supported platform).
It is certainly my preference to centralize maintenance.
Any time you can centralize the control of something,
maintenance becomes cleaner, and is forced
to be consistent (much like database normalization).

gnatprep obviously helps to address this issue for the "gnat
world". But IMHO Ada could be well served if there was a standard
for an Ada preprocessors.  Its use of course would be optional
(for the purests and those situations where it is not needed),
but a standard would make Ada code more easily portable.

Failing that, everyone must bake their own solution to this
problem. Many maintain that by centralizing problem code into
separate libraries works well enough. But this does not help
in the cases where a product can be compiled with different
options turned on or not (say from a Makefile). In other cases,
it may mean enhancements involve maintenance of several parallel
modules, instead of one centralized location.

I havn't checked to see if any current discussions are
taking place about the possibility of standardizing a
preprocessor. But if were to guess, it has been discussed
and summarily dismissed on religious grounds ;-)

-- 
Warren W. Gay VE3WWG
http://ve3wwg.tk