Re: Ada success story

[ted@grebyn.com (Ted Holden)]

 
 
From Terri Richard: Ohio State University Computer
 
>I think most people who read this conference are really tired of hearing
>this.  If you love C++, great.  Just don't hassle productive conversations
>on THIS conference.  I for one am extremely tired of hearing it.
 
Is somebody actually forcing you to read these articles??  Just hit the "n"
key and don't worry... be happy!  (Apparently, the truth doesn't set
everybody free;  some, it just makes squeamish...)
 
 
From Jeffrey Stewart: Software Engineering Institute, Pittsburgh, PA
 
>>The literature and every conversation I have ever had with real-world
>>people who have been forced to actually attempt to USE Ada have totally
>>convinced me of the failure of this project.  By the same token, C++
>>could very nearly, if not entirely, fill the bill.
 
>Well Ted, I guess you never talked to me or the group I worked with at
>Hercules Defense Electronics.
 
>We have just finished a project to implement all of the control software
>plus some signal-processing software, in Ada, for a Millimeter-Wave radar
>seeker for the Maverick missile.
 
>Its about 7500 lines of code, based on an object-oriented design, does
>signal-processing, provides dual-loop control for the antenna, provides
>mission control for the entire missile, plus some other things.  And it
>does it at 600Hz, on a 10MHz 80286.  There is NO ASSEMBLER.  The goal
>was a complete Ada artifact, and the goal was achieved.
 
You're not really telling us very much here...  most importantly, what
all did you have to turn off?  What if anything differentiated your use
of Ada from most people's use of Pascal (other than cost)?
 
>Projects that DO have a problem with Ada tend to fall into the following
>categories :
 
>     The classic "10 pounds of stuff into a 5 pound bag" problem.  You won't
>     solve this with C either.  Many times, the requirements stack the deck
>     against you.  Period.
 
>     Less than production-quality compilers.  I'll admit this was a problem,
>     and is less so every day.
 
Perhaps you are referring to a recent comment by one of your fellow Ada
supporters on the net:
 
 
      "My only problem with Ada at this point is the cost ($ and hardware
      resources) of a compiler for my XT clone. Both IntegrAda and Janus require
      more memory than DOS 4.01 leaves available.  This is BAD DESIGN.  There
      is no excuse for a 551K executable in a PC (pass 2 of Integrada).  Janus
      Ada requires > 580K available to run, and rumor has it that the Integrada
      compiler is a repackaged Janus compiler."
 
The funny thing is, I don't really have that much of a problem with your
basic thesis other than the fact that it's import is rather limited.
Basically you seem to be saying that, of the ten or fifteen Ada
compilers in the DOS world which we hear about, you were able to pick
one which, given enough restrictions, could produce code which would
execute rapidly enough for a fairly sophisticated project, without
saying anything about compile times and the resultant impact on
development times.  I have no real problem with that.
 
You seem, however, to have little appreciation of the situation in which
the average poor slob who is forced to use Ada finds himself.  The Ada
compiler he gets to use is just the one provided on the contract by, you
guessed it, the lowest bidder.   Now, this would seem to indicate that
there is something to be said for keeping your basic programming
language spec simple enough that more than one out of ten or fifteen
compiler vendors might succeed at building a reasonable compiler given
10 years (as Ada has had).  For instance, I would lose little or no
sleep at the prospect of being forced to use the lowest bidders C
compiler between MicroSoft, Borland, Zortech, Watcom...  Could you say
the same as regards Ada compilers?
 
In the same vein, when you attempt to enforce something like Ada upon the
numbers of people involved, you should have some idea of how these
people live;  for instance the fact that a great many of them are just
now getting Unisys/Arrete 5000/95 and/or similar computers to work with.
Or, for instance, the fact that almost none of them are having any luck
keeping Ada programmers or "software engineers" around as regular
government workers.  Consider that you will soon have to justify Ada on
a cost basis, and that almost all Ada programmers are contractors...
minor detail worth mentioning.
 
>     Whiners who will use every excuse to blame the language rather than the
>     design.  The two ARE different, design and implementation, don'cha know?
>     Many of these projects fail due to poor design, regardless of
>     implementation language.
 
When you hear the whole world whining, there's probably some real reason
for it.
 
>I refuse to assign percentages to these categories.  Let that be an exercise
>for the reader.
 
>By the way Ted, part of the rationale for Ada was that the techniques and
>languages in current use (mid 70's) would be inadequate for the million-plus
>SLOC systems anticipated for the 90's.  What are the successful C-language
>projects of this size?
 
UNIX, WordPerfect, DBASE-IV, X-11, Quattro, Sprint, News...  What if
any million-line projects have actually been successfully implemented in
Ada (without having major language problems in 10% of the code)?
 
The truth is, I wouldn't want to be using C on huge projects anymore;
that's what C++ and the object-oriented paradigm are about.  C++ has it
now.  Ada might have it in the future, but:
 
        1. How many years from now?
        2. At what cost in clunk factor in a language whose clunk
           factor is already too high for most users.
 
In the Zortech C++ manual, p 62, the authors note:
 
        "An overwhelming design requirement was that the speed,
        efficiency, and simplicity of expression of the C language was
        to be retained in the new language."
 
The corresponding statement, ten years from now, will probably read:
 
        "The unholy clunk factor of Ada just got a lot unholier..."
 
 
The best description of the applicability of object-oriented
programming to large projects which I have seen is the section of the
Pinson/Weiner book (Intro to OOP & C++) which shows a C++ linked-list
application with and without late-binding, along with the requirements
for maintaining the two sections of code.  Night and day.
                                         
>To sum up, Ada DOES work, for its intended purposes.  Maybe you should
>consider becoming an equal opportunity basher, i.e., cite some C/C++
>failures as well.  (And don't tell me there aren't any.  Your use of
>absolute terms is part of what detracts from your credibility.)
 
It isn't really like there aren't any other losers in the realm of
computer languages:  there are Fortran, COBOL, PL/1, Forth, Prolog, and
any number of others;  I would actually choose Ada over one or two of
these for certain kinds of applications, since Ada is at least a
structured language.  The thing is, these others are just quietly
withering away on the vine and/or dying of old age of
their own accord and in accordance with ordinary free-market principals;
they do not seem to require a stake through the heart.
 
The thing is, when you go to ENFORCE a language on the entire U.S.
military, you owe it to them to ensure that that language is the best
available, and not one which, according to everything in print, most
compiler vendors have never learned to deal with after ten years.
Actually, it would be better to simply allow our much-touted
free-enterprise/free-market system to do it's thing;  that's what's
supposed to seperate us from the communists, isn't it?
 
Ted Holden
HTE