Path: utzoo!attcan!uunet!mcvax!enea!sommar
From: sommar@enea.se (Erland Sommarskog)
Newsgroups: comp.lang.c++
Subject: Re: C++ vs Ada / how to name kittens
Message-ID: <4098@enea.se>
Date: 21 Nov 88 21:09:38 GMT
Organization: ENEA DATA AB, Sweden
Lines: 93

This has of course nothing to do with C++. I guess I ought to cross-post
to comp.lang.ada and direct follow-ups there, but I thought I should
save the readers of that group. As for you C++ fans I care less about  
you, since I don't read this group myself.

Ted Holden borrows Bob Burch's account (bob@imspw6.UUCP) and writes:
>I have watched a 30 line Ada program take 27 minutes to compile on a
>multi-processor 68020 device with nothing else happening on it.  

And I have seen an Ada compiler compile in just as the same time as any
compiler at that machine. I *have* seen compilers behaving something like 
the one Ted describes, but that was five years ago. Things have changed.
A lot. True it takes longer time to get a program through the compiler.
To some extent this could be blamed on language complexity, but mostly to
the fact that the compiler finds more of your errors. 

>I have always had the impression that in computer science generally and
>in government computer science more particularly, there has been about
>an 80 - 20 mix of people who design things on paper and people who make
>anything breathe and live on real machines.  C began with real machines,
>real computer users.  The idea seems to have been:

I haven't dealt with C, but I have dealt with langauges where simple
implementation was considedered more important than a complete 
langauge. The look powerfull to begin with, until you stumble on
all the cases which were not important to the implementors but to me.
It's a question to look around the corner. It's good to have the
language now, but it's not good to be stuck with all the limitations
forever.

>Ada is unbelievably slow, an unbelievable resource hog, involves constant
>dilemmas over which is the real OS today, Ada or UNIX, Ada or Dos etc. i.e.

I ran a very simple test on our machine here. (VAX 780, 4.3 BSD) A word- 
counting program in Ada (Verdix 5.41) took 2-3 times longer time than
old "wc". On the other hand, the Pascal program was 5 times slower than
Ada and the Fortran 3 one times. And don't jump to conclusion about the
Ada-C relationship. Verdix uses far from all possibilities the VAX 
architecture offers (their compiler is a multi-target one). Looking at 
the code I'm surprised that the programs run as fast as they do.

>do we use Ada tasking, again, frighteningly slow, or ordinary UNIX tasking
>and inter-process communication, Ada source control or SCCS, etc.  Naturally,
>the Ada task manager and the UNIX process scheduler clash.  My experience

Ada wasn't designed to run real-time applications on a time-sharing 
system, one should have this is mind. Its real-time primitives were
intended for embedded systems. Probably, with today's computers you
have to resort to the target systems own process handling if you
want to write a fast multi-tasking application in Ada for a system
like Unix or VMS. Not really satisfactory. but what other options
does other langauges offer you?

>The verbiage hides the logic.  When every
>variable name looks like:
> 
>"NUMBER_OF_CROWS_SALLY_ANNS_GRANDMOTHER_SHOT_WITH_HER_12_GAUGE_-
>LAST_TUESDAY",
> 
>then a single subroutine call (involving several
>such variables) can take up a whole page.  In my own scheme of
>things, I try to keep literature and programming separate.

So what says that you must use such names in Ada? If you love long
names you can have them in C too. I prefer readable names rather than
obscure abbreviations, but I don't fall into exagerations. 

>Ada threatens to leave DoD stranded and technologically
>backwards.  The better class of programmers coming out of the
>schools will be used to the 2 second compiles of Turbo C and
>Turbo Pascal.  

If they prefer to find the errors themselves and wasting a lot of
time of testing, instead of having the machine finding them. 
Personally I prefer if I can trust as much as possible on the 
computer. I have enough of things to think of anyway.

>If the program stays in effect for 5 years,
>I'll make even more money teaching those same people Russian, which
>they'll need at that time.  You'd better believe, the Russians program in
>C.

If they do, I would stay calm. They will get a core dump before they 
can do any harm.

To conlude: your Ada flames are based on a total misconception. 
Apparently you haven't been working with any serious Ada compiler. 
Come back when you have.
-- 
Erland Sommarskog
ENEA Data, Stockholm
sommar@enea.se
"Frequently, unexpected errors are entirely unpredictable" - Digital Equipment