HDTenEightyP/NetNews huggingface dataset:
From: SAHARBAUGH@ROO.FIT.EDU
Newsgroups: comp.lang.ada
Subject: An Ada Program Does What It Says?
Date: 3 Jan 93 14:15:00 GMT
Distribution: world
Organization: The Internet

First lets review:

Pascal wrote, in part:  "An Ada program does what it says."

I raised a warning that this is not true and cited one example 
from Bryan & Mendal's book.  

Alex Blakemore pointed out that a program with concurrency 
cannot be counted on to execute in a certain order (or words to 
that effect).

Mike Feldman said that I choose a weak example from the book 
to make my point.

That brings us up to date.

I searched B&M's book and noted each example program whose 
output is "indeterminate" or "implementation dependent".  I 
noted the page number on which the answer appears.  

volume 1: 26 80 111 115 118 119 121 122 125 128 242 257 
270 275 335 340  volume 2: 32 37 47 78 81 104 106 107 151 
152 178 183 238 240 246 274 276 291 293 308 309

I suggest vol 1 pg 335 for first reading.  It is language 
lawyer level.

My warning stands.  Ada code looks deceptively readable.  The 
reader must understand the language translator and the 
runtime environment to be able to correctly read an Ada 
program.

I recall that the ARTEWG produced an "Ada catalog of runtime 
dependencies".  I suggest contacting Mike Kamrad for a copy.

I am really into an area addressed by people looking at 
"portable" "reusable" Ada code.  Perhaps they have developed 
proven techniques for developing translator and runtime 
environment independent Ada code.  

sam harbaugh
---
Newsgroups: comp.lang.ada
From: firth@sei.cmu.edu (Robert Firth)
Subject: Re: New Arcadia/IRUS AFLEX-AYACC release
Organization: Software Engineering Institute
Date: Fri, 8 Jan 1993 08:02:30 EST

In article <EACHUS.93Jan7193852@goldfinger.mitre.org> eachus@goldfinger.mitre.org (Robert I. Eachus) writes:

>  First does any warrant of merchantability reside
>in any free software product?  Probably not.

In the UK, very probably, yes.  This was made explicit in the old
original Sale of Goods act in 1880.  Blackstone's summary reads:

	"In a sale or by sample, there is an implied
	 warranty of merchantableness" [UK Law Times, 1885]

This was further reinforced by a case in the 1930s whose details
I forget but you can look it up.  The distributor was a pharmaceutical
company that gave free sample of its products to doctors as a means
of advertising them.  When one of them killed a patient, the company
argued just that - there was no implied warranty because no sale.
They lost.  The issue is not whether you charge for the product, but
the fact that you distribute it.

Robert

Newsgroups: comp.lang.ada
From: bdorough@eng.auburn.edu (Barry L. Dorough)
Subject: Matrix Package for Ada
Organization: Auburn University Engineering
Date: Tue, 12 Jan 1993 03:10:13 GMT




I am looking for a package generic or otherwise that does matrix
operations if anyone knows of such a package (free_ware) or other
(will pay if have to) please email me at bdorough@eng.auburn.edu.

			Thanks in Advance,
			Barry

Newsgroups: comp.lang.ada
From: zeil@renenutet.cs.odu.edu (Steven J. Zeil)
Subject: Re: Bindings for Micro Soft Windows to Ada
Organization: Old Dominion University, Norfolk, VA, USA
Date: Fri, 8 Jan 1993 18:38:08 GMT

In article <1993Jan6.025639.18809@seas.gwu.edu> mfeldman@seas.gwu.edu (Michael Feldman) writes:
>
>   Meridian offers a pretty good Windows-based compiler with a usable "thin"
>   binding to the Windows API. I take it that this is what you were after.
>


I purchased Meridian's OpenAda Windows 1.0 last month and have been
quite disappointed.  

The biggest problem is that any use of exception renaming causes the
code generator to crash.  The kicker is that, because Direct_IO and
Sequential_IO both rename the exceptions from IO_Exceptions, any
instantiation of these two packages causes the crash.  Meridian's
customer support acknowledges the problem and says that it "might" be
fixed in the next version.  They did not respond to my queries as to
whether the other compilers in their line (e.g., the DOS version)
share this problem. This effectively kills any chance I had of
making practical use of their compiler.


In addition, there are built-in limitations that I find annoying. No
more than 64K of static variables total across all packages. No more
than 64K of run-time stack space total across all tasks.  Even if I
chose to write my own Direct_IO package (without exception renaming)
to overcome the bug noted above, these would be quite hard for me to
live with.


                                                     Steven Zeil
Newsgroups: comp.lang.ada
From: bortzmeyer@cnam.cnam.fr (Stephane Bortzmeyer)
Distribution: world
Organization: CNAM
Subject: Crash your compiler (Was: Ada Readability, Book Reference)
Date: Tue, 05 Jan 93 19:15:36 +0100
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X-References: <1992Dec30.035143.10291@seas.gwu.edu> <1993Jan4.093155.11894@nobeltech.se> <1993Jan4.174424.5699@seas.gwu.edu> <1993Jan5.115003.29978@sei.cmu.edu>
X-Mts: smtp

In article <1993Jan5.115003.29978@sei.cmu.edu>,
progers@ajpo.sei.cmu.edu (Pat Rogers) writes:
> In article <1993Jan4.174424.5699@seas.gwu.edu> mfeldman@seas.gwu.edu
(Michael Feldman) writes:
...
> >This is interesting. I take it, then, that 1.0/3.0 will be flagged by
> >the compiler, because - unless a rational representation is being
> >used, which is always possible, I suppose - there aren't enough bits
> >in a megabyte to evaluate it exactly. Do compilers use rationals
> >for this?  I'll be back later, after a test or two of this!
...
> About seven years ago I saw this program (I think by John Squires) on
> info-ada (this is a reconstruction from memory). See how long it takes 
> your compiler to give up on it -- use a batch queue if you can, especially 
> on a virtual memory machine.  If it does eventually compile, you can just 
> add lines until it won't...

Here are some results:

1) Sony/Risc under News/OS (sort of Unix BSD) with the Alsys/Systeam compiler:

% time ada.c ../killer.ada
Compiling:  /users/labinf/bortz/ada/essais/killer.ada
line 0, col 1, restriction:
         Overflow of digit pool in constant table
compiler error at end of compilation unit:
         Compilation in SEMANTIC aborted
PROCEDURE  KILLER
  **** Number of Errors              :     2
29.7u 0.5s 0:39.54 76.6% 337+196k 72+9io 354pf+0w

(Thirty CPU seconds before giving up.)

2) DECstation under Ultrix (sort of Unix BSD) with the DEC compiler:

% time ada.c ../killer.ada

(Twenty minutes of CPU time later, the experimentator went to bed.)

Does anyone have such a collection of "compiler killers"?

Stephane Bortzmeyer           Conservatoire National des Arts et Metiers	
bortzmeyer@cnam.cnam.fr       Laboratoire d'Informatique
                              292, rue Saint-Martin			
tel: +33 (1) 40 27 27 31      75141 Paris Cedex 03
fax: +33 (1) 40 27 27 72      France	

"C'est la nuit qu'il est beau de croire a la lumiere." E. Rostand

					
	
Xref: sparky comp.lang.ada:3949 comp.compilers:2139
From: eifrig@beanworld.cs.jhu.edu (Jonathan Eifrig)
Newsgroups: comp.lang.ada,comp.compilers
Subject: Re: Compiler Construction in Ada
Keywords: courses, Ada, books
Date: 12 Jan 93 00:12:03 GMT
Article-I.D.: comp.93-01-066
Reply-To: eifrig@beanworld.cs.jhu.edu (Jonathan Eifrig)
Organization: The Johns Hopkins University CS Department

bpb9204@tamsun.tamu.edu (Brent Burton) writes:
>This format [hand-coded lexer/parser in Pascal, using the Dragon book]
>proved to be quite effective and educational.  Through
>previous work at IBM, I had experience with lex and yacc already and a
>good understanding of the parsing process.  However, the hand-coding
>approach was, I feel, mandatory to learn the important underlying
>algorithms and to better understand the roles lex and yacc play.  After
>the the discussion about LL and LALR parsers, I could finally understand
>the shift/reduce and reduce/reduce errors. ;-)

	Having been involved in teaching the compiler design course here
at Hopkins for the last two years, I thought I'd put my two cents in.
(For the record, the first two years used the Dragon book, with a bunch of
hand-written supplements, while the last year used Fischer/LeBlanc (C
version)).

	Basically, I'd agree with Brent's motives: it's very important to
understand the theory of shift/reduce parsing and backing-up DFA lexing
before one can use the lex/yacc family of tools effectively.  However, I
don't think that necessarily means writing lexers/parsers by hand.

	Here at Hopkins we structure the course around the semester
project, which traditionally has been writing a Toy-to-C translator, where
Toy is a Pascal-like language with integer and function types, ref and
array constructors, and first-class functions.  (Function closures are
what make the translation non-trivial).  The first half of the
semester-long course's lectures are all on parsing theory, using Gough's
excellent "Syntax Analysis and Software Tools" as a supplemental text.
However, the students build their lexers and parsers using C, lex, and
yacc.  I really don't see that subjecting students to the torture of
cranking out lexers for a grammar with something like thirty keywords
accomplishes much other than convincing them one is a sadist.  Don't even
think about LR parsers with non-trivial action functions; debugging even
the machine- generated ones is a horror show.

	I think that it's much better to get the student's up and running
with a useable parser in a short amount of time.  This lets them
concentrate on the more interesting parts of the compiler, like the
type-checker, and experiment with different run-time strategies.  Yes, the
theory of LR parsing is very important to learn, but I don't believe that
can only be done by "rolling your own."
--
Jack Eifrig (eifrig@cs.jhu.edu)       The Johns Hopkins University, C.S. Dept.
-- 
Send compilers articles to compilers@iecc.cambridge.ma.us or
{ima | spdcc | world}!iecc!compilers.  Meta-mail to compilers-request.
From: courtel@cenatls.cena.dgac.fr (Nicolas Courtel)
Newsgroups: comp.lang.ada
Subject: Re: Announcing PARADISE version 3.0
Date: 4 Jan 93 11:00:07 GMT
	<1992Dec24.185524.8327@netfs.dnd.ca>
Organization: Centre d'Etudes de la Navigation Aerienne, Toulouse, France

>>>>> On Thu, 24 Dec 1992 18:55:24 GMT, BERRYMAN@orca.drep.dnd.ca (DON BERRYMAN) said:

DON> In <1992Dec22.134206.5394@cenatls.cena.dgac.fr> courtel@cenatls.cena.dgac.fr writes:

> The source code is available on ftp.cenatls.cena.dgac.fr, in directory
> pub/export:
> -rw-r--r--  1 50       32         241167 Dec 22 13:10 paradise-3.0.tar.Z

DON> I tried to FTP from ftp.cenatls.cena.dgac.fr and cenatls.cena.dgac.fr and
DON> could not connect. Does anyone know the numeric TCPIP address???

The numeric address is 143.196.1.6. As our machines reboot every night at 1:20
(0:20 GMT), it may be an explanation for impossible connection.

DON> Don Berryman
DON> Defence Research Establishment Pacific
DON> Canadian Forces Base Esquimalt
DON> Victoria, BC, CANADA, V0S-1B0
DON> 604-363-2731    604-363-2856fax
DON> berryman@orca.drep.dnd.ca

--
Nicolas Courtel - courtel@dgac.fr

>>>        The goal of science is to build better mousetraps.         <<<
>>>            The goal of nature is to build better mice.            <<<
From: yow@sweetpea.jsc.nasa.gov (Bill Yow)
Newsgroups: comp.lang.ada
Subject: Re: INFO-ADA Digest V92 #489
Date: 11 Jan 93 15:14:11 GMT
Organization: MDSSC

In article <CMM-RU.1.3.725031677.lejeune@pilot.njin.net>, lejeune@PILOT.NJIN.NET (Urban LeJeune) writes:
|> The Meridian phone number is 1-800-221-2522

Meridian has changed its 800 number it is now 1-800-653-2522.

|> If it's for educational puproses ask for Brad Pederson.
|> 
|> Urb
|> 
|> Urban A. LeJeune                  lejeune@pilot.njin.net
|> Department of Computer Science    W2DEC
|> Stockton State College            FAX   609-652-4858
|> Pomona, NJ 08240                  Voice 609-652-4477  Home 609-296-5856

						Later,
						Bill Yow
						(713) 283-4051
						yow@sweetpea.jsc.nasa.gov
						byow@mcimail.com

My opinions are my own!			
Newsgroups: comp.lang.ada
From: eachus@goldfinger.mitre.org (Robert I. Eachus)
Subject: Re: New Arcadia/IRUS AFLEX-AYACC release
Organization: The Mitre Corp., Bedford, MA.
	<EACHUS.93Jan7193852@goldfinger.mitre.org>
	<1993Jan8.080230.22934@sei.cmu.edu>
Date: Fri, 8 Jan 1993 16:55:32 GMT


    Again I am not a lawyer, and certainly not an English barrister,
but there is a major difference between free samples and a product
that is not intended for sale.  If you go beyond merchandise, just
where do you stop?  Or to put it another way, is the disclaimer at the
bottom of my postings in violation of EC law?

    P. S. In the states the same sort of thing applies, but usually
the treatment is that the implied warrant of merchantability resides
in merchandise OFFERED for sale, whether or not actually sold.  Thus
it covers such things as consignment goods, test periods, etc.

--

					Robert I. Eachus

with Standard_Disclaimer;
use  Standard_Disclaimer;
function Message (Text: in Clever_Ideas) return Better_Ideas is...
Newsgroups: comp.lang.ada
From: srogers@teenwolf.mcc.com (Steve Rogers)
Subject: Re: C++ vs. Ada -- Is Ada loosing?
Organization: MCC, Austin, Texas
Date: Mon, 4 Jan 1993 15:22:23 GMT

In article <MMEYER.92Dec31114831@m2.dseg.ti.com> mmeyer@m2.dseg.ti.com (Mark Meyer) writes:
>
>	I'm new to this group, basically because I'm new to Ada.
>Even so, I just have to comment on this:
>
>In article <1992Dec21.161105.9344@mcc.com> srogers@teenwolf.mcc.com (Steve Rogers) writes:
>> The edition I am looking at is the 3rd edition.
>
>	Are you sure?  I'm looking at the 3rd Edition myself.  When
>was your copy printed?  This book seems to go through a reprint twice
>every year, and mine's from 1990.  I only ask because both your
>examples of errors seem to be in error themselves, at least as far as
>my copy is concerned.
>
>> Two examples: The FRAME program on page 325 violates LRM 9.1.4 - the
>> type of the task cannot be used as a typemark within the task itself.
>> It's easy to see what the program means, but it doesn't comple. 
>
>	No, it doesn't violate 9.1.4.  I could tell that by
>inspection.  I was even able to compile it (after removing references
>to the FRAME package - I don't know how to get our compiler to build a
>library and someone else has the manual).  Nowhere in the task body of
>FILTER does anyone try to use FILTER as a type.  In fact, on p. 327
>Barnes specifically states, "(The use of the function MAKE_FILTER is
>necessary to overcome a rule that in the body of a task type its name
>refers to the current task and not the type.)"

The date on my copy is 1989.  The FILTER task references itself on page 326.
I suppose the error was found and corrected in later editions.

>> There is a task example on page 311 that has nested accepts for the
>> same entry which violates LRM 9.5(8).  Again, its clear what the
>> program intends, but it has been simplified in a way that keeps it
>> from compiling.
>
>	I was able to compile this program too.  In my copy of the
>book, the accepts are not nested.  Do you have the 3rd Edition,
>printed in 1990?  Maybe your book was printed earlier?

Whoops!  I misread this one.  

The correction of the FRAME error answers the larger question of whether
or not the errors were intentionally included to make the examples
"easier" to understand.  It appears that this is NOT the case.

-- 
| Steven Rogers  MCC/ESL  3500 West Balcones Drive
| Austin, Texas 78759-6509  (512) 338-3691 srogers@mcc.com
From: rlk@VisiCom.COM (Bob Kitzberger)
Newsgroups: comp.lang.ada
Subject: Re: Stars FTP Site is it closed?
Keywords: Stars FTP Ada
Date: 12 Jan 93 21:04:37 GMT

yow@sweetpea.jsc.nasa.gov (Bill Yow) writes:

>Has the stars.rosslyn.unisys.com (128.126.164.2) FTP site closed?

A few months ago there was a message from someone at STARS that
said that the STARS machine will no longer be accessible via FTP.
Perhaps this was only for the machine at source.asset.com, though.

It's a shame, because FTP is much, much, much easier to use than
the beast that you find if you dial the STARS' repository.  The
repository software has brought me to tears on several occasions.  At one
point, I was able to find the Unix directory that held the STARS
source code, and use good old 'ls' and 'grep' to find what I was looking
for, but that back door has been closed recently.  You _have_ to use
the nasty repository front end.  

Contact Ms. Tanya Lawrence (703-620-7929) for more information on
gaining access to the Unisys STARS Center.  

	.Bob.
----------------
Bob Kitzberger          VisiCom Laboratories, Inc.
rlk@visicom.com         10052 Mesa Ridge Court, San Diego CA 92121 USA
                        +1 619 457 2111    FAX +1 619 457 0888
From: kislow@PILOT.NJIN.NET (Chris)
Newsgroups: comp.lang.ada
Subject: Re: INFO-ADA Digest V92 #458
Date: 5 Jan 93 03:13:19 GMT
Distribution: world
Organization: The Internet


  Also there is a complier called Janus/Ada  which in my mined is really
 neat. It uses a sort-a-kinda WINDOWS atmosphere which is very helpful
in all the programming that I have done. So here is another complier.
Newsgroups: comp.lang.ada,comp.compilers
From: jipping@cs.hope.edu (Mike Jipping)
Subject: Compiler Construction in Ada
Reply-To: jipping@cs.hope.edu (Mike Jipping)
Organization: Hope College Dept of CS
Date: Thu, 7 Jan 1993 12:42:45 GMT
Keywords: courses, question, comment

I'm looking at teaching Construction in the Spring semester.  The course
includes writing a compiler (all the way through code generation for a
SPARC machine) for a language I specify.  In the past, we have had a
Pascal compiler, and the class has used Pascal to write their projects.

Now the Pascal compiler is gone.  And I'm looking for the appropriate
language in which to write the compiler for the project.  The language and
the project require the student to write a top-down, recursive descent
parsing compiler.  Therefore, a language allowing nested subprogram
definition would be very preferrable.

We have what looks like a good Ada compiler (from Meridian) for the Sun
workstations.  So I'd like to use Ada to write the compiler.  

My question(s): is there any pitfalls to look out for here?  has any one
done this?  what special disadvantages are there here?

Thanks in advance.

      Mike Jipping
      Hope College Department of Computer Science
      jipping@cs.hope.edu  (BITNET: JIPPING@HOPE)
[I'd use whatever language had the best debugging support.  I've written
recursive descent code in C and (a while ago) in Fortran without any
trouble. -John]
-- 
Send compilers articles to compilers@iecc.cambridge.ma.us or
{ima | spdcc | world}!iecc!compilers.  Meta-mail to compilers-request.
Newsgroups: comp.lang.ada
From: garyp@rmtc.paramax.com (Gary Palangian [RMTC/ISP])
Subject: First-Time C
Organization: Paramax Systems
Date: Mon, 11 Jan 1993 21:06:36 GMT

Hey Now Everybody,

    I have been working with Ada for about 8 years now.  I think
Ada is the best thing to happen to large systems development since
magnetic disk.  Part of my previous job was comparing Ada and C so
I know a little about C programming.  

    Our customer is probably going to make a decision to move from
Ada to C on my project.  I am concerned about our ability to
control the software engineering process, especially module integration,
using C as a language.  Can anybody offer advice or a reference text
that discusses large system development and the particular implementation
and coordintation issues one should expect/plan for if C were the implementation
language.

    Please, I don't wan't to start an Ada/C thing.  And I will not
say any more about changing from Ada to C.  I would appreciate
concise and concrete information for managing large systems development
using C, especially from those with an Ada background.


Thanks,


Gary P.
From: magnus@lglsun.epfl.ch (Magnus Kempe)
Newsgroups: comp.lang.ada
Subject: Re: Enum's start at 0?
Date: 7 Jan 93 08:09:43 GMT
Organization: Ecole Polytechnique Federale de Lausanne

Timothy M. Schreyer asks:
: ... why do string indices start at 1? :-)

A closet Pythagorean in the Ada design team got rational arithmetic
into the compilers; similarly, a disciple of Parmenides strove to
find the one in the many and upheld that what is not, is not.  Thus,
String indices start at 1, not in the void of 0.

Ada is the language for those who have love of wise programming, a
derived type of philosophers.
-- 
Magnus Kempe            "I have sworn ... eternal hostility to every form of
magnus@lglsun.epfl.ch    tyranny over the mind of man."  -- Thomas Jefferson
Newsgroups: comp.lang.ada
From: progers@ajpo.sei.cmu.edu (Pat Rogers)
Subject: Re: Ada Readability, Book Reference
Summary: rational arithmetic and universal expressions 
Organization: Ada Joint Program Office
Date: Tue, 5 Jan 1993 11:50:03 EST

In article <1993Jan4.174424.5699@seas.gwu.edu> mfeldman@seas.gwu.edu (Michael Feldman) writes:
>
>Hmmm. How on earth could 1.0/3.0 be exact? What would the value be?
>
>I checked my Annotated LRM (thanks to Karl Nyberg!) and found AI-00209:
>"An implementation can refuse to evaluate a static universal real expression
>only if there are insufficient resources to evaluate the expression exactly,
>e.g., if there is insufficient memory available. Inexact results must not
>be delivered."
>
>This is interesting. I take it, then, that 1.0/3.0 will be flagged by
>the compiler, because - unless a rational representation is being
>used, which is always possible, I suppose - there aren't enough bits
>in a megabyte to evaluate it exactly. Do compilers use rationals
>for this?  I'll be back later, after a test or two of this!
>
>Mike Feldman
>------------------------------------------------------------------------
>Michael B. Feldman
>co-chair, SIGAda Education Committee
>

About seven years ago I saw this program (I think by John Squires) on
info-ada (this is a reconstruction from memory). See how long it takes 
your compiler to give up on it -- use a batch queue if you can, especially 
on a virtual memory machine.  If it does eventually compile, you can just 
add lines until it won't...

Pat Rogers
progers@ajpo.sei.cmu.edu

-------- cut here --------

procedure Killer is

  A : constant := 1.0 / 3.0;

  B : constant := A * A * A * A * A * A * A * A * A * A * A * A * A;
  C : constant := B * B * B * B * B * B * B * B * B * B * B * B * B;
  D : constant := C * C * C * C * C * C * C * C * C * C * C * C * C;
  E : constant := D * D * D * D * D * D * D * D * D * D * D * D * D;
  F : constant := E * E * E * E * E * E * E * E * E * E * E * E * E;
  G : constant := F * F * F * F * F * F * F * F * F * F * F * F * F;
  H : constant := G * G * G * G * G * G * G * G * G * G * G * G * G;
  I : constant := H * H * H * H * H * H * H * H * H * H * H * H * H;
  J : constant := I * I * I * I * I * I * I * I * I * I * I * I * I;
  K : constant := J * J * J * J * J * J * J * J * J * J * J * J * J;
  L : constant := K * K * K * K * K * K * K * K * K * K * K * K * K;

begin
  null;
end Killer;
Newsgroups: comp.lang.ada