Re: How come Ada isn't more popular?

[Markus E Leypold <development-2006-8ecbb5cc8aREMOVETHIS@ANDTHATm-e-leypold.de>]

Hi Pascal,

Pascal Obry <pascal@obry.net> writes:

> Markus E Leypold a �crit :
>
>> No, I asked, how you define expressiveness (generally), not, what is
>> so expressive in this pragma. But never mind. It's not important.
>
> Sorry I did not understand that! For me, a high expressiveness in a
> programming language is how easy/simple it is to declare something that
> can be quite complex underneath.

Ludovics example was quite the opposite (verbose if precise). I think,
that expressiveness can not be defined or measured very well. Perhaps
as number of programming patterns that are supported and their
flexibility. So object orientation introduces more expressiveness when
compared with procedures, Hindley-Milner type systems when compared
with languages that have no parameterized types, templates (C++) would
also introduce more expressiveness (don't flame me, we are talking
"expressiveness" now, not safety), range sub-typing Ada style is also
added expressiveness (which on the other side is absent from the
Hindley-Milner type systems ...), functions as closures and 1st class
citizens allow to abstract over iteration patterns (fold, map, etc),
so this also introduces more expressiveness. And so on.

I do not agree with your definition that just measures the ratio
between "things happening underneath" and the construct you write in
your program. If I'd agree, I also had to concede that 

 #include <stdio.h> 

is terribly expressive, because it pulls in such a lot of
functionality with one line (actually I think Fortran programmer would
agree :-) -- since there is no preprocessor defined in Fortran (up to
77 at least), they abuse the C preprocessor to reuse data definitions
and this like).

Perhaps we should ask: Which programming patterns / paradigms does
the language support? I realize that is terribly vague.

To widen the scope of this discussion a bit: I've been using some
10-20 languages in the last 2 decades intensively and looked upon
perhaps double as many. I'm amazed about the narrowing of perspective
I perceive with a number of participants in this discussion and the
other one (where someone asked for an Ada example for his book). Ada
still has it's place in the world, I think, but it would be good to
admit that things have changed a bit during the last 25 years. There
is a lot to be learned from Ada. Exclusive focus on it and ignoring
that not every piece of software fits into the Ada niche (which I
perceive to be reliable embedded programming) won't help to promote
it. I sometimes even doubt it can be rescued in the long run.

(That isn't against you, I'm just adding this not here, because I
can't decide where else).


Regards -- Markus