Re: Teaching new tricks to an old dog (C++ -->Ada)

["Jerry Coffin" <jcoffin@taeus.com>]

Martin Krischik wrote:

[ ... ]

> You are aware that SCADE supports more then one target programming
> language?

Yes, I'm aware that Ada is mentioned in their marketing information,
but looking through several 3rd-party web sites, I haven't been able to
find any mention of anybody ever having actually used this ability. I
was talking specifically about Airbus' use, and looking at:

http://www.esil.univ-mrs.fr/~spc/rcs02/slides/Baufreton.pdf
and:
http://www.systemes-critiques.org/jslc2001_slides/FrancoisXavier_Dormoy.ppt

indicates that they're consistently using C, not Ada. I also mentioned
use in other transport, and if you look at slide 12 of the second link
above, you'll notice where it specifically says this was done with C
code as well.

So far, I've found several references that mention generating C code,
some that don't specify the language, zero that mention having
generated Ada.

> On the one hand this supports you claim -  If you use SCADE then
> programming language is indeed irrelevant.

First of all, I don't recall having made any such claim. What I have
said is that choice of programming language is but one factor among
many, and that I believe it's only rarely the single most important
factor.

Second, this seems to assume that all the code is generated by SCADE,
and none written directly. This does NOT seem to be the case -- if you
look at page 6 of:

http://scilabsoft.inria.fr/events/05_11_03/ESTEREL.pdf

you'll see that they only claim 70% of the code was generated by SCADE.
Given the size of project we're talking about, the remaining 30% is a
_significant_ amount of code. It seems likely to me that if they were
using Ada for the hand-written code, they'd generate Ada as well.

[ ... ]

> PS: I find the order they give in there drop-down box quite telling
> with SPARK-Ada at the top and Standart C at the bottom while at the
> same time all marketing texts say first C then Ada. I supports my
> suspicion that languages are more often chosen marketing effort
> then by actual facts.

Even if we assume that all the references I've found that didn't
specify a programming language were using Ada, it still appears that C
is being used considerably more than Ada.

What I find telling is that somebody is so desparate to find _anything_
to favor their position that they'll read the order of strings in a
listbox as really meaning something -- especially when they're
apparently just in alphabetical order!

I think it's also worth noting that SCADE itself appears to be written
in C++. While they don't specify this directly, the API they supply to
make it programmable is specifically stated as being for C++ (e.g.
http://www.liveware.com.br/pdf/telelogic_scade.pdf
page 23). While they could undoubtedly provide a C++ API from Ada, it
seems most likely to me that if it was written in Ada, use from Ada
would be supported (and mentioned). I'm sure writing in Ada and ONLY
supporting C++ is a theoretical possibility, but it strikes me as quite
unlikely.

--
    Later,
    Jerry.

The universe is a figment of its own imagination.