Early Ada Mistakes (was: Re: += in ada)

Early Ada Mistakes (was: Re: += in ada)

[Marin David Condic]

Wes Groleau wrote:
 > Marin David Condic wrote:
 >
 >> which to run the compilers and nobody was willing to "subset" the
 >> language to get some portion of it working reliably & efficiently
 >> in a
 >
 > Janus was willing.  I had a copy runnable on a CP/M 64 K machine.
 > Never did anything with it.
 >
I owned one of those too for a PC. Also the Telesoft compiler. Both couldn't
figure out how to get generics implemented, so they ended up with
butt-ugly, non-portable kludges in order to make something vaguely
resembling Text_IO work. Eventually, this got fixed, but, as I observed,
it put people off and made them believe that all the promises were just
hype - that Ada *was* just to big and complicated and inefficient and
would never meet its promises of portability.

BTW, I liked the RR product, so please don't throw stones at me Randy!
However, I don't have anything nice to say about Telesoft - mostly for
bad business practices - so those guys are free to go pile sand. Except
they don't exist anymore. Wonder why? ;-)

As for subsets - that was viewed as heresy at the time. Nobody official
wanted to sanction a subset and most of the potential users didn't seem
to want there to be one. In point of fact, subsets got made anyway, but
there was no "conventional" subset anyone could count on and there were
non-portabilities (as I observed with Text_IO). This ought to be a 
"Lesson Learned" - if the vendors are going to end up doing it anyway, 
then its better to accommodate it in some manner so it gets done in a 
*standard* way.

I thought it would be A Good Thing(tm) had there been some kind of
semi-official subset that could have been validated so that a compiler
might have been "Level 1 Compliant". That may have let compiler writers
come out with something that would have met the needs of us guys with
really small target processors and/or inexpensive home computers. We
would have been able to play the game and do so in a way that was
"Portable". As technology improved, vendors might have more easily
become "Level 2 Compliant" and customers could have upgraded as their
hardware grew to meet the needs.

But that's all 20/20 hindsight. Perhaps if we get to have *another* DoD
mandated programming language.... :-)


 >

 >> The value of strong typing in particular was not seen as "user
 >> friendly". They tried to write "Adatran" code and found it
 >> difficult. So
 >
 >
 > And people on the other extreme, who thought that just because the
 > language offered something, you had to use it.
 >

Yup. You still see that today and not just with Ada. People go off and take
a course and get all hyped up about some particular set of features and
have to run off and make use of each and every one in their first program.

We still occasionally see religious wars here over the use of standard
("Predefined" - Sorry Robert.) Integer and Float types. Some folks
believe it is morally wrong under any circumstances *not* to define your
own types for every conceivable use. Others are more lax about it.

I'm in the "Others" category, but I did learn a lesson about not using
the predefined type Integer in an embedded machine where later, when we
needed to meet requirements to guarantee saturation on overflows, I was
unable to override the "+" (etc) operators. Had I defined my own integer
type, I could have done this. Fortunately, it wasn't too hard to review
the code and determine that we were O.K. without it & get waivers from
the requirement.



 > I remember one program that had 26 tasks when given to me.  When I
 > was done with it, it had five, and still met all its requirements.
 >
I recall one that was built by the Special Olympics Software Development
Team at a company that shall remain nameless. They had been sent off to
Object Oriented Programming School (on the Short Bus) and came back and
turned *everything* into a task. As well you can imagine, this
complicated analysis of program behavior immensely. It could have been
done a hell of a lot simpler, but, well, they *were* the Special
Olympics Software Development Team. :-)

MDC

-- 
======================================================================
Marin David Condic
I work for: http://www.belcan.com/
My project is: http://www.jsf.mil/NSFrames.htm

Send Replies To: m c o n d i c @ a c m . o r g

     "All reformers, however strict their social conscience,
      live in houses just as big as they can pay for."

          --Logan Pearsall Smith
======================================================================

Re: Early Ada Mistakes (was: Re: += in ada)

[Robert I. Eachus]

Marin David Condic wrote:

> I thought it would be A Good Thing(tm) had there been some kind of
> semi-official subset that could have been validated so that a compiler
> might have been "Level 1 Compliant". That may have let compiler writers
> come out with something that would have met the needs of us guys with
> really small target processors and/or inexpensive home computers. We
> would have been able to play the game and do so in a way that was
> "Portable". As technology improved, vendors might have more easily
> become "Level 2 Compliant" and customers could have upgraded as their
> hardware grew to meet the needs.

There were actually two, pretty well understood by all compiler 
developers.  The first was the Pascal subset, this was basically 
everything in Ada that was also in Pascal.  A lot of compiler developers 
either modified a Pascal compiler to compile this subset, or built a 
tool to convert from the Pascal subset of Ada into Pascal.

The next step up was the Pascal superset.  This was basically everything 
in Ada except chapters 9 (Tasking), 12 (Generics) and most of 13.  This 
was the language that most compiler developers used--and possibly still 
do--to implement the Ada run-time.  Of course, a lot of people would say 
that some compilers, such as the original Telesoft compiler were only 
useable with the Pascal superset.  I am not one of them.  I never found 
the original Telesoft compiler useable.  But then again, maybe I never 
found the right Pascal subset to use with it.

-- 
                                             Robert I. Eachus

"Quality is the Buddha. Quality is scientific reality. Quality is the 
goal of Art. It remains to work these concepts into a practical, 
down-to-earth context, and for this there is nothing more practical or 
down-to-earth than what I have been talking about all along...the repair 
of an old motorcycle."  -- from Zen and the Art of Motorcycle 
Maintenance by Robert Pirsig

Re: Early Ada Mistakes (was: Re: += in ada)

[Ed Falis]

On Wed, 22 Oct 2003 16:25:44 -0400, Beard, Frank Randolph CIV 
<frank.beard@navy.mil> wrote:

> I believe they were bought out by IBM.  We were using their compiler
> on the IBM Mainframe for Space Station.  If you ever wondered how to
> make compiler messages more obscure, compile on MVS.
>

Telesoft was bought by Alsys after the latter was bought by Thomson.  The 
remnants of the original Telesoft development group are still part of 
Aonix, I think (though I wouldn't swear it).

- Ed

Re: Early Ada Mistakes (was: Re: += in ada)

[Ed Falis]

On Wed, 22 Oct 2003 17:39:56 -0400, Beard, Frank Randolph CIV 
<frank.beard@navy.mil> wrote:

> I thought that was TeleUSE, not TeleSoft, but you would know better than
> me.  Sorry for the misinformation.  At least, I'm pretty sure it was the
> TeleSoft compiler we used on the IBM Mainframe.

Oh, it's easy to get confused - I'm still confused about why the orignal 
Alsys US office was shut down.  But's that's the software industry, eh?

Someone should write a biography of Ada along the lines of "Soul of a New 
Machine".  All of the dramatic elements are there for the general 
entertainment.

- Ed

Re: Early Ada Mistakes (was: Re: += in ada)

[Alexandre E. Kopilovitch]

Ed Falis wrote:

>Someone should write a biography of Ada along the lines of "Soul of a New 
>Machine".  All of the dramatic elements are there for the general 
>entertainment.

I have read "Soul of a New Machine" about 15 years ago, and I still remember it.
And I don't think that it is possible to compose something similar about Ada,
because a problem of hardware (in broad sense, it shouldn't be necessarily
computers). Hardware must be in place, you can't produce really good literature
about software only... because that software must have a valid purpose (without
known purpose all software-related problems will look just as a kind of soap
opera). And I think that this is particularly true for Ada. So, if you include
both Ada and hardware, you'll get not a small book, but a huge volume.

Then, look at the characters: those in "Soul..." are good persons, but even
the main character is still not heavyweight - and what we have in Ada history
in this respect?

Although... if you ask Tim Rice, perhaps he will find it an interesting idea? -:)



Alexander Kopilovitch                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia

Ed Falis wrote:

>Someone should write a biography of Ada along the lines of "Soul of a New 
>Machine".  All of the dramatic elements are there for the general 
>entertainment.

I have read "Soul of a New Machine" about 15 years ago, and I still remember it.
And I don't think that it is possible to compose something similar about Ada,
because a problem of hardware (in broad sense, it shouldn't be necessarily
computers). Hardware must be in place, you can't produce really good literature
about software only... because that software must have a valid purpose (without
known purpose all software-related problems will look just as a kind of soap
opera). And I think that this is particularly true for Ada. So, if you include
both Ada and hardware, you'll get not a small book, but a huge volume.

Then, look at the characters: those in "Soul..." are good persons, but even
the main character is still not heavyweight - and what we have in Ada history
in this respect?

Although... if you ask Tim Rice, perhaps he will find it an interesting idea? -:)



Alexander Kopilovitch                      aek@vib.usr.pu.ru
Saint-Petersburg
Russia

Re: Early Ada Mistakes (was: Re: += in ada)

[Marin David Condic]

Yea, there was the "Pascal-Like Subset" that was a starting point for a 
lot of vendors, but a) it wasn't any kind of approved, validated 
standard, so you couldn't be sure of any kind of portability (every 
vendor had their own rules about what they were going to implement) and 
b) there were things that had to be included that were way off of the 
standard in order to make it work. The most obvious was Text_IO: You 
couldn't do I/O for anything except text (numeric types, enumerations, 
etc.) without generic instantiation and, as you observed, that was the 
"Level 2" part. So compilers had to come up with some sort of hack-job 
to give you I/O for floats, integers, etc., without having generics. 
Double-Plus-Ungood for developing anything you hoped to make portable.

I realize it all got fixed eventually, but it *did* leave a bad taste in 
  the mouths of a lot of users. Ada was supposed to be this wonderful 
language that was going to be portable across all machines and all 
compilers - but the wonderful parts were not there and the portability 
was no better - perhaps worse - than your average Fortran or C compiler. 
Disillusionment followed rapidly.

Even today, I think there might be some food-value in a "standard" 
subset that would be aimed at small embedded machines. (Assuming anyone 
wants to try to venture into that market again.) Spark might make a nice 
start - except that it isn't a "Standard". I don't know enough about 
Spark to know if it limits itself to things that would hack the language 
down to something easily targeted to small embedded machines. It just 
might be valuable to have something that could easily fit a small target.

MDC



Robert I. Eachus wrote:
> 
> There were actually two, pretty well understood by all compiler 
> developers.  The first was the Pascal subset, this was basically 
> everything in Ada that was also in Pascal.  A lot of compiler developers 
> either modified a Pascal compiler to compile this subset, or built a 
> tool to convert from the Pascal subset of Ada into Pascal.
> 
> The next step up was the Pascal superset.  This was basically everything 
> in Ada except chapters 9 (Tasking), 12 (Generics) and most of 13.  This 
> was the language that most compiler developers used--and possibly still 
> do--to implement the Ada run-time.  Of course, a lot of people would say 
> that some compilers, such as the original Telesoft compiler were only 
> useable with the Pascal superset.  I am not one of them.  I never found 
> the original Telesoft compiler useable.  But then again, maybe I never 
> found the right Pascal subset to use with it.
> 


-- 
======================================================================
Marin David Condic
I work for: http://www.belcan.com/
My project is: http://www.jsf.mil/NSFrames.htm

Send Replies To: m c o n d i c @ a c m . o r g

     "All reformers, however strict their social conscience,
      live in houses just as big as they can pay for."

          --Logan Pearsall Smith
======================================================================

Re: Early Ada Mistakes (was: Re: += in ada)

[Ole-Hjalmar Kristensen]

>>>>> "EF" == Ed Falis <falis@verizon.net> writes:

    EF> On  Wed,  22  Oct  2003  17:39:56 -0400,  Beard,  Frank  Randolph  CIV
    EF> <frank.beard@navy.mil> wrote:


    >> I thought that was TeleUSE, not TeleSoft, but you would know better than
    >> me.  Sorry for the misinformation.  At least, I'm pretty sure it was the
    >> TeleSoft compiler we used on the IBM Mainframe.

    EF> Oh,  it's easy  to get  confused -  I'm still  confused about  why the
    EF> orignal  Alsys US  office was  shut down.  But's that's  the software
    EF> industry, eh?


    EF> Someone should write a biography of  Ada along the lines of "Soul of a
    EF> New Machine". All of the  dramatic elements are there for the general
    EF> entertainment.


    EF> - Ed

If I remember correctly, both the TeleSoft compiler and the TeleUse
UIMS came from the same company (TeleSoft).

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