Re: Quality systems (Was: Using Ada for device drivers? (Was: the Ada mandate, and why it collapsed and died))

[Preben Randhol <randhol+abuse@pvv.org>]

soft-eng wrote:
> I don't agree that Ada is likely to be particularly useful
> for catching errors in a professional environment -- say 2-3%
> of the actual errors at best.  If it's catching more than
> that, I don't see how you can have good people.

If it only catches 2-3% of the errors then there must be a huge amount
of bugs in professional environment software. If you look at all the
buffer overflow errors then these programs will be riddled with bugs as
buffer overflow lands in your 2-3% category.

Another advantage of Ada is the readability of the source code. In order
to catch your errors you have to read through the source not simply test
it to see if it runs. I believe IBM once published some data of how
many percent was discovered by reading the code versus just testing it.
I think the numbers where something like 60%-70% and 20-30%
respectively. Miscrosoft used only the latter method earlier IIRC, what
they do now, I don't know.

On quality: http://www.fastcompany.com/online/06/writestuff.html

> But good people can certainly make projects succeed using
> many kinds of tools, including Ada.

A great many things are possible, yet not practical. (Isaac Asimov)
Or in other words you can probably make a huge complex system in
assembly code, but it will take you a couple of decades to get the job
done.

> The only thing is they might privately grumble more, and may
> often have to get C/C++ libraries written by outside vendors
> or themselves.  

If you are interfacing with an OS written in C you would have to
make bindings to the C part even if you use C++.

> (Usually there are excuses - We could
> have done it all in Ada, except for this and that...
> But excuses or not, if you need a graphics library for
> a new device, you would typically not write it in Ada.  You

Why not?


-- 
Preben Randhol                    http://www.pvv.org/~randhol/