Smalltalk and Ada

Smalltalk and Ada

[Karl A. Nyberg]

[Ed. - forwarded]

Date: Mon, 2 May 88 12:15:22 pdt
From: umd5!anna.STANFORD.EDU!tracz (William Tracz)
Subject: Smalltalk and Ada

I am currently in the process of implementing the first 4 layers of the
Smalltalk class hierarchy in Ada.  I thought that before I went any further
I should check to see if anyone has done it before.

So, has anyone in Adaland tried to emulate a Smalltalk environment?
(No graphics in this versions)

Will Tracz -- your friendly used-program salesman

Smalltalk and Ada

[Raheel]

Hi,
 I am writing a paper about the comparison of the Java and Smalltalk
languages. Could anybody give me some info, pointers or resource links
it would be very helpful to me.
 Thank you.

Re: Smalltalk and Ada

[Preben Randhol]

On 4 Dec 2001 11:56:57 -0800, Raheel wrote:
> Hi,
>  I am writing a paper about the comparison of the Java and Smalltalk
                                                    ^^^^^^^^^^^^^^^^^^

What does this have to do with Ada? Your subject says: Smalltalk and Ada

Which languages are you looking at really?

Preben
-- 
 ()   Join the worldwide campaign to protect fundamental human rights.
'||}
{||'                                           http://www.amnesty.org/

Re: Smalltalk and Ada

[Raheel Ahmad]

Sorry must have been drinking when i wrote that. I indeed meant Smalltalk
and Ada. Please disregard the earlier..
As I said any info would be helpful
"Preben Randhol" <randhol+abuse@pvv.org> wrote in message
news:slrna0qcrp.3aj.randhol+abuse@kiuk0156.chembio.ntnu.no...
> On 4 Dec 2001 11:56:57 -0800, Raheel wrote:
> > Hi,
> >  I am writing a paper about the comparison of the Java and Smalltalk
>                                                     ^^^^^^^^^^^^^^^^^^
>
> What does this have to do with Ada? Your subject says: Smalltalk and Ada
>
> Which languages are you looking at really?
>
> Preben
> --
>  ()   Join the worldwide campaign to protect fundamental human rights.
> '||}
> {||'                                           http://www.amnesty.org/

Re: Smalltalk and Ada

[Nick Roberts]

I suspect you won't find any existing comparisons between Ada and Smalltalk.

One interesting observation I have made is the way in which devotees of both
languages consider their language (Ada or Smalltalk) to be especially suited
to 'software engineering'.

Of course, I suspect different people have different ideas of what 'software
engineering' means.

To some it seems to be about constructing software which operates in close
connection with hardware; I guess hardware engineers culturally like to
supplant hardware engineering concepts onto software. Ada's areas of
application tend to be very much here (more as a result of the history of
the language rather than its features).

To others, especially Smalltalk people I think, it is purely about the
construction of software, but constructing it in ways which have analogies
to good engineering principles (e.g. overspecification of a structural
member's strength, as compared to redundancy and robustness techniques in a
program). Smalltalk has had some remarkable successes in the building of
large, complicated applications quickly (i.e. economically) yet with an
unusually high level of quality (for that kind of software).

Smalltalk is a great language for building (high-level) application software
fast. You can start building ideas straight away: you make a list of
entities in the application domain, and then make a class or object for each
one; add suitable methods, and test them out, interactively; add interface
components; add database and/or filing components; connect stuff up, and lo!
you've got the beginnings of a solution. Because Smalltalk is strong on
things like default behaviour, incremental refinement, and closeness of
correspondence between the software model and the real-world model, you tend
to be able to push forward rapidly, without having to keep going back and
changing your design, or lots of implementational details. Smalltalk has a
small syntax, and always has an 'object browser', so it can be easy to
learn.

However, Smalltalk has some serious disadvantages. Compilation is one. Some
Smalltalks can compile to native code, but oh so slowly. Too slow to be a
part of the development cycle. It is therefore useless for most low-level
programming. Even then, the native code produced will never be as good as
that produced by a program reasonably well written in a 'traditional'
compiling language (like Ada). Another disadvantage is the fact that
Smalltalk makes the assumption that the target is the host, and that this
must be powerful enough to support Smalltalk's typically huge memory
requirements and a full GUI.

Ada has a lot of hidden strengths. It's a very practical language. It has
all the (important) advantages of 'traditional' compiled languages (COBOL,
Fortran, Algol, C, Pascal, Modula, C++, etc.), but with solutions to (or
improvements on) most of the major practical shortcomings of these
languages. Nevertheless, Ada is able to live pretty directly in traditional
language environments, and can target embedded and 'tiny' environments. It
can interface directly with object code produced by compilers of other
languages. It is excellent at the low level, and adequate at the high level;
this mix can be very potent in some circumstances. Ada has a fair few
oddities and subtleties of use; it may be quite quickly learnt, but is less
quickly mastered. The best mitigation for this is that Ada compilers catch a
great many mistakes (that would be caught only dynamically or not at all by
other languages).

Smalltalk is all-pervasively object-oriented (it was the language that
invented the concept). Ada 95 provides object-oriented programming
facilities, but these are (almost) additional to the core language, and can
generally be ignored if not required. One interesting comparison between
Smalltalk and Ada is that they both support only single-inheritance (a
class/object can only have one parent class).

The one really big -- stark, even -- difference between Smalltalk and Ada is
in standardisation: you will find that every different Smalltalk product is
highly incompatible with nearly every other one; you will find that very
nearly every Ada implementation is very highly compatible with all the
others.

You will find useful information on Ada at:

http://www.adapower.com

I think you will find some useful information about Smalltalk at:

http://www.dnsmith.com/SmallFAQ/SmallFaq.html

and:

http://www.smalltalk.org.au/index.html

as well as, of course, the Usenet news group:

comp.lang.smalltalk

Hope this gives you a little food for thought!

--
Best of luck,
Nick Roberts

Re: Smalltalk and Ada

[Wes Groleau]

Nick Roberts wrote:
> Smalltalk is all-pervasively object-oriented (it was the language that
> invented the concept). Ada 95 provides object-oriented programming

I know little about Simula or Smalltalk, but I believe the former
was around in 1967.  Wasn't the latter 1980?

-- 
Wes Groleau
http://freepages.rootsweb.com/~wgroleau

Re: Smalltalk and Ada

[Preben Randhol]

On Fri, 07 Dec 2001 09:19:41 -0500, Wes Groleau wrote:
> 
> 
> Nick Roberts wrote:
>> Smalltalk is all-pervasively object-oriented (it was the language that
>> invented the concept). Ada 95 provides object-oriented programming
> 
> I know little about Simula or Smalltalk, but I believe the former
> was around in 1967.  Wasn't the latter 1980?

Simula

   The SIMULA programming language was designed and built by Ole-Johan
   Dahl and Kristen Nygaard at the Norwegian Computing Center (NCC) in
   Oslo between 1962 and 1967. It was originally designed and
   implemented as a language for discrete event simulation, but was
   later expended and reimplemented as a full sacle general purpose
   programming language. 
   
   [...]

   Although SIMULA is an extension of the programming language ALGOL 60,
   it is not a true extension of it. SIMULA retains the spirit of ALGOL
   60 and includes that language as a subset, except for some minor
   exceptions.

   [...]

   Although SIMULA never became widely used, the language has been
   highly influential on modern programming methodololy. Among other
   things SIMULA introduced important Object-Oriented programming
   concepts like classes and objects, inheretance and dynamic binding.

taken from:

http://www.engin.umd.umich.edu/CIS/course.des/cis400/simula/simula.html

Preben Randhol
-- 
 ()   Join the worldwide campaign to protect fundamental human rights.
'||}
{||'                                           http://www.amnesty.org/

Re: Smalltalk and Ada

[Georg Bauhaus]

Wes Groleau <wwgrol@sparc01.ftw.rsc.raytheon.com> wrote:
: 
: 
: Nick Roberts wrote:
:> Smalltalk is all-pervasively object-oriented (it was the language that
:> invented the concept). Ada 95 provides object-oriented programming
: 
: I know little about Simula or Smalltalk, but I believe the former
: was around in 1967.  Wasn't the latter 1980?

I recall to have had a book in my hands with writings
of Dijkstra and Hoare (iirc), from the late 50s, one of which
is about object oriented things.  I could see if I find
this again, if you want.


Georg

Re: Smalltalk and Ada

[Nick Roberts]

"Wes Groleau" <wwgrol@sparc01.ftw.rsc.raytheon.com> wrote in message
news:3C10CFFD.A09EA803@sparc01.ftw.rsc.raytheon.com...
>
> Nick Roberts wrote:
> > Smalltalk is all-pervasively object-oriented (it was the language that
> > invented the concept). Ada 95 provides object-oriented programming
>
> I know little about Simula or Smalltalk, but I believe the former
> was around in 1967.  Wasn't the latter 1980?

Indeed I merely repeat others' misinformation (it's a human disease), and
stand to be corrected :-/

--
Best wishes,
Nick Roberts

Re: Smalltalk and Ada

[Gisle Sælensminde]

In article <9v18tj$c5rhj$1@ID-25716.news.dfncis.de>, Nick Roberts wrote:
> "Wes Groleau" <wwgrol@sparc01.ftw.rsc.raytheon.com> wrote in message
> news:3C10CFFD.A09EA803@sparc01.ftw.rsc.raytheon.com...
>>
>> Nick Roberts wrote:
>> > Smalltalk is all-pervasively object-oriented (it was the language that
>> > invented the concept). Ada 95 provides object-oriented programming
>>
>> I know little about Simula or Smalltalk, but I believe the former
>> was around in 1967.  Wasn't the latter 1980?
> 
> Indeed I merely repeat others' misinformation (it's a human disease), and
> stand to be corrected :-/

Simula was definitly the first OO language, and was developed about 1965.
The simula developers did not use the term "Object oriented" though. 
I think (but is sure) that the Smalltalk developers did that. Smalltalk
was developed in the seventies and the current version was finished in 
1980. 

BTW, Simula was my first programing language. The University of Bergen, Norway
used it as the first programing language until 96. Then it became too difficult
to port the simula compiler to new architectures. As far as I know, the Simula
langage is dead by now. After Simula, java took over the role as a first 
programming language.

--
Gisle S�lensminde ( gisle@ii.uib.no )   

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going
to land, and it could be dangerous sitting under them as they fly
overhead. (from RFC 1925)

Re: Smalltalk and Ada

[Georg Bauhaus]

Gisle S?lensminde <gisle@apal.ii.uib.no> wrote:

: Simula was definitly the first OO language, and was developed about 1965.

http://www.ifi.uio.no/~kristen/FORSKNINGSDOK_MAPPE/F_OO_start.html

: Then it became too difficult
: to port the simula compiler to new architectures. As far as I know, the Simula
: langage is dead by now.

Hmmm,
http://www.stator.um.edu.mt/simula/cim.html
http://staff.um.edu.mt/jskl1/asu/index.html

Georg

Re: Smalltalk and Ada

[Gisle Sælensminde]

In article <9v2r12$nle$1@a1-hrz.uni-duisburg.de>, Georg Bauhaus wrote:
> Gisle S?lensminde <gisle@apal.ii.uib.no> wrote:
> 
>: Simula was definitly the first OO language, and was developed about 1965.
> 
> http://www.ifi.uio.no/~kristen/FORSKNINGSDOK_MAPPE/F_OO_start.html
> 
>: Then it became too difficult
>: to port the simula compiler to new architectures. As far as I know, the Simula
>: langage is dead by now.
> 
> Hmmm,
> http://www.stator.um.edu.mt/simula/cim.html
> http://staff.um.edu.mt/jskl1/asu/index.html
> 
> Georg

We used the Lund University simula compiler, and the maintainers of
it did not want to maintain it anymore, and the 'cim' compiler was not 
compatible with some the code developed at the university of Bergen 
(and Oslo). It was also used as an excuse for 'upgrading' to a more 
modern and fashionable programing language.

As far as I know, It's not used as a first language anymore at any 
university, and I don't know about any code written in Simula still in 
production. I would like to be proved wrong here. I could not find any 
information about that on the web pages above.       

--
Gisle S�lensminde ( gisle@ii.uib.no )   

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going
to land, and it could be dangerous sitting under them as they fly
overhead. (from RFC 1925)

Re: Smalltalk and Ada

[John]

I believe BETA, which is now free, is the semi-official successor to
Simula. Interesting language and development environment, but doesn't
look like it has built up much of a user base yet.

http://www.mjolner.com/mjolner-system/beta_en.php

/John

Re: Smalltalk and Ada

[Al Christians]

Three or two years back, the Smalltalk advocates were proud that the
JWARS system, a big DoD battlefield simulation was being done in
Smalltalk instead of Ada or anything else. Anyone know if this 
project has accomplished what it was intended to accomplish?  If the
DoD has learned anything one way or another from this project?

TIA

Al