Re: Ada vs C++ vs Java

[gwinn@ma.ultranet.com (Joe Gwinn)]

In article <78g0oj$8sb$1@nnrp1.dejanews.com>, robert_dewar@my-dejanews.com
wrote:

> In article
> <gwinn-2201990017500001@d5.dial-1.cmb.ma.ultra.net>,
>   gwinn@ma.ultranet.com (Joe Gwinn) wrote:
> > Had a formal C language reference been available back
> > then, I would have used it.
> >
> > You keep trying to make it more than I ever claimed for
> > it, an exercise in knocking strawmen down.  I think I
> > accurately described the data point, and leave it to the
> > readers to draw whatever conclusions they wish.
> 
> Perhaps naively most readers will expect that if you
> describe such a data point, then at least you ascribe
> *some* significance to it. That is certainly the
> implication from your original post!
> 
> If indeed you agree that this is a nonsense comparison that
> tells absolutely nothing of any value at all, then we have
> no argument!
> 
> > You keep trying to make it more than I ever claimed for
> > it.  I think I accurately described the data point, and
> > leave it to the readers to draw whatever conclusions they
> > wish.
> 
> Again, we assumed that at least *you* thought that your
> observation had some value (you did after all spend some
> time doing it). In fact neither of these observations says
> anything at all useful about language comparisons.
> 
> Producing completely bogus comparisons, and then saying you
> have accurately described these comparisons seems
> disingenuous. At the very least you were trying to convey
> the impression that something useful was being measured!

The evidence is what it is, and we cannot do much about it, fifteen year later.


> > You have gnu C, C++ and gnat at your fingertips.  What do
> > the various components weigh?
> 
> It is not something I would spend 30 seconds looking at,
> because the answer to this question would convey little of
> value!

If perfect metric existed, we would use them.  Absent perfection, we use
what's avaialble.  I take it the answer isn't to Ada's perceived
advantage.


> > But, let's get down to brass tacks, using personal
> > experience and whatever expertise and instincts we can
> > muster to sort some languages into a rough complexity
> > ranking.
> 
> Gosh, it almost seems like you did not bother to read my
> last note, the whole point of which was that to lump the
> different aspects of complexity into a single metric does
> not work.

Clearly, I didn't accept the argument, which boiled down to saying that
because we couldn't find a perfect metric, we should do absolutely
nothing.  I know what would happen if I tried that kind of perfectionist
argument out on my boss.  Rough measures are better than no measures at
all.


> > 3.  Ada83 versus K&R C?  Ada83 is a factor more complex,
> >     by all metrics, than K&R C, by universal experience.
> 
> Since this seems to be your most obvious case for expecting
> an unconditional yes vote, I will choose this one to
> illustrate.

Yep.  OK.


> First of all K&R C is ill defined. Lack of definition
> results in a lot of uncertainty of semantic details, and
> this kind of uncertainty leads to significant complexity:

We already agreed that Ada83 is better defined than K&R C, so further
discussion of that is beside the point.  Please answer the original
question, yes or no.  


> For example
> 
>     int a[10];
>     ...
>     for (p = a; p < &a[10]; p++) ...
> 
> is this valid K&R C? Difficult to say, probably the answer
> is no, but on the other hand, C programmers use this
> construct all the time. It is of course legal in ANSI C by
> virtue of a very special (and rather odd and non-orthogonal
> rule).

Yep.  But, beside the point.


> If we are going by the metric of ease of formal
> description, I would say Ada 83 is far simpler than K&R C,
> just because so much remains to be done in the latter case.
> That work of course is what took the ANSI C committee so
> much effort to sort out.

Yep.  But, beside the point.


> As for ease of use, this depends what you are doing, if you
> have to write a multi-threaded application in a portable
> manner, then in one sense it is impossible with K&R C, but
> in pragmatic practice it means struggling with some
> pthreads package. These packages are typically ill-defined
> and all sorts of non-portable glitches occur. Ada 83 is by
> comparison a far simpler environment. The same goes for
> code that needs exceptions.

Perhaps.  But, beside the point.


> From an implementation point of view, C may be simpler,
> though even there it is not quite cut and dried. For
> instance extraction of good aliasing information of the
> same quality can require FAR more work in C than in Ada, or
> even be quite impossible. Furthermore, the need for good
> aliasing information in C is much more important because of
> the lack of strong typing of pointers in the Ada sense.

Perhaps.  This is your area of expertise.  

I guess this is a "yes", sort of.


> About the only place where I would say that C is clearly
> simpler than Ada 83 is in the comparison of informal
> descriptions, where K&R shows that a fairly short informal
> description of C is possible.

Has anyone written such an informal description of Ada83 as well?  I never
saw such a description, simple yet possible to program from, and one has
to wonder if it's possible to write such a thing.


Joe Gwinn