Re: Ada and QNX

[Igor Kovalenko <kovalenko@home.com>]

Robert Dewar wrote:
> perhaps because mere technical superiority is not enough.
> Remember that the really successful programming languages
> in terms of usage (COBOL, Visual Basic, and I guess even
> Excel Macro language should count) do not succeed solely
> because of technical excellence, but because of historical
> factors.
> 
> After all Fortran succeeded over Algol-60, and for SURE
> that was not a matter of superiority of language. I also
> note that Windows-9X succeeded over OS/2, which is even
> more surprising.
> 
> Technical folks always suppose that technical excellence
> is enough to succeed in the market place. I would have
> thought that the dominance of Microsoft in the operating
> system arena (even in the MS DOS days!) would have perhaps
> reminded people that this is not the case, but ....

Did you intentionally overlooked the fact that some new languages found
their way into mainstream and some did not? They all faced similar
uphill battle against historical issues and human prejudice.
Nevertheless, Java did hit the streets. And C++ did, roughly at the same
time as Ada failed. Sure C++ had advantage of being similar to C, but
then Ada is similar enough to Pascal. Perl emerged as major scripting
language although I doubt there was anything like dedicated marketing
support and there were and still are many competitors. How would you
explain all that?

Also, comparing programming languages to OSes is really stretched
analogy, to put it mildly. A new OS faces much more challenge to make
its way, due to hardware support and applications availability issues.
No such problems with PL - if one have to write new code anyway, it does
not matter which language to choose from compatibility point of view.

> > Perhaps my personal doubts aren't that personal, huh?
> 
> and perhaps they most certainly are, a lot of decisions are
> made on the basis of uninformed personal prejudice of the
> kind you exhibited.

I suppose you always do exhibit absolute lack of personal prejudice, so
that gives you right to blame me for it.

> Actually Ada would be an excellent technical choice for writing
> an operating system, the reason that the current operating
> systems are written in some other language is mostly historical.

Historically OS were written in assembler. Then people started to use C
and they don't seem to be inclined to change that. You can call it
historical, I will call it practical.

> > And by the way, many people say that GCC does not generate
> > good code for C
> 
> Well many people say all sorts of unsupported things (you
> demonstrate this principle in your post)

You could not fail to mention that, could you? Which exactly unsupported
thing did _I_ say AND claimed it to be anything but matter of my
personal taste? I do not share the view of those who denounces GCC. I
said 'some people say' merely to point to simple fact that there are
such people. Based on that I asked how people can so easily claim GNAT
to be efficient given that the language places a lot more burden onto
compiler. I did not say it is impossible for GNAT to be good but I said
that it probably trades efficiency of code for portability (by which I
mean ability of compiler to generate code for different
architectures/OSes).

Note, I'm not blaming either GCC or GNAT for such a tradeoff - in fact I
supported such tradeoff in an another discussion.

> It would be easy to satisfy your curiosity, the compiler and
> sources are out there.

That kind of answer usually means you hardly can explain that yourself.

> You suspect wrong, in fact RV is programmed using standard
> POSIX primitives that are typically available on all commonly
> used systems.

That is rather vague statement. Even if 'standard' (whatever that means)
POSIX primitives were available on all systems (which is not true), then
POSIX is about portability, not efficiency. 

> Now of course RV is a fairly high level
> abstraction, which you use if you want to abstract at this
> level. If you want lower level things, then you use them
> in Ada (indeed there is nothing to stop you using any
> low level system dependent gizmo that you would use in
> C if you like).
> 

If you throw away fairly high level stuff of Ada then it might not be so
much better than C++. Why bother learning it and convincing management
to use it?

> In general you seem a bit too willing to substitute your
> ill-informed guesses for facts.
> 

That's 3rd time in single post you're pointing out to my misbehavior.
Just can't miss a chance, can you? If this thread is gonna be about me
personally, we might want to move it to alt.sex.selebrities because I'm
gonna be a star if you keep it that way 8-}

- igor