What Mac developers think of Ada !

What Mac developers think of Ada !

[Siow Wey Hua]

Hello all,

Below are responses of some Mac developers from Apple's OpenSource
(Darwin Public Source mailing list) to my question of rewriting Darwin
(a BSD 4.4 unix) in Ada 95 !.

Personal comments at the bottom of each numbered mail.

----------------------------------------------------------------------------------------

1.
Date: Thu, 26 Aug 1999 04:29:48 -0400
From: "Ronald C.F. Antony" <rcfa@cubiculum.com>
Subject: Re: Coding Darwin in Ada 95

> If Darwin is to be unique among the unixes, why not rewrite or
recompile
> the bulk of the Darwin OS (written in C++) in Ada 95 (high level OO
> procedural-based language, ISO 8652:1995) instead of Objective C or
C++
> ?

Because a) it's a lot of work, b) means everything would have to be
reoptimized from scratch, c) C and Unix are like Strawberries and
Champagne,
they belong together.
Further, strongly typed and dynamic OOP are for the most part at odds
with
each other. Ada may be able to replace C++, but it's hardly a fit
replacement for the task ObjC is supposed to do.
Your suggestion would be much more fit when we were talking about
OpenVMS, than when talking about a Unix OS with an dynamic OOP
environment.

> No other language I know so far beats Ada 95 in terms of reliability
> (strongly typed), portability, reusability.

In terms of portability Ada is beaten by C, Java, Cobol..., in terms of
reusability by SmallTalk, ObjC, etc. and in terms of reliability by a
slew of smaller languages. Ada is huge, and thus the likelyhood of
having bugs in the compiler etc. are much higher than for a small, lean
and mean language.

> Besides since all unixes are
> renowned for their breadth of software development capabilities,
writing
> unix or macosx programs in Ada 95 should not be too difficult, given
> that GNAT exists (GNU Ada Translator by Ada Core Technologies) and
other
> good ones exist for unix and wintel platforms. C++ to Ada 95
conversion
> tools exists as well.

Depends. For application programming ADA may or may not be appropriate,
depending on how much dynamism is required. Interfacing ADA to Cocoa
wouldn't be exactly trivial...
----------------------------------------------------------------------------------

The arguments are rather subjective (and not very good in specifics),
lacking objectivity.
Because I am a newcomer to Ada 95 and advanced programming concepts, my
arguments are rather weak. How does one and who shall define the terms
portability, reusability, reliability ? and in what context and scope ?
From Ada 95's perspective ?
----------------------------------------------------------------------------------

2.
Date: Thu, 26 Aug 1999 06:34:28 -0700
From: Creed Erickson <creed@landooz.com>
Subject: Re: Coding Darwin in Ada 95

At 12:46 AM -0700 8/26/99, Siow Wey Hua wrote:
>...why not rewrite or recompile the bulk of the Darwin OS (written in
C++)
> in Ada 95 (high level OO procedural-based language, ISO 8652:1995)
instead
> of Objective C or C++?

Two words: Zero Mindshare.

- ---
Creed Erickson (mailto:creed@landooz.com)
Professional Nitpicker, Instigator, and Software Test Pilot
"There are two ways to write error-free programs.
Only the third one works." -Anon
----------------------------------------------------------------------------------

Too bad, no big deal though. The man's entitled to his own opinions.
----------------------------------------------------------------------------------

3.
Date: Sat, 28 Aug 1999 13:13:37 -0400
From: "Ronald C.F. Antony" <rcfa@cubiculum.com>
Subject: Re: Responses

> I definitely recognise that Objective C (odd man out of the C family
with
> SmallTalk roots and to a certain extent marginalised) is the best way
> forward for Darwin of the present, but what will happen after 5 to 10
years
> when Objective C becomes obsolete ?
> Since Ada is an ISO standard, it will be reviewed and improved in the
next
> millennium, Ada is an all-rounded language despite its military
background,
> and is a good candidate for the MacOS 1X to be coded in the next
decade or
> so.

You make the false assumption that ObjC *will* become obsolete.
History has shown us that the dynamic languages tend to have much
longer life spans than the static ones. Lisp, one of the earliest
programming languages is still alive and kicking, and most importantly,
considered state of the art. Fortran and Cobol are still alive, due
to the huge code base out there, but few people would call them
"state of the art". Meanwhile a slew of static languages came and
went, while languages like SmallTalk stay.
I give ObjC more staying power than the average static language.
Ada may be an exception, because of similar reasons as hold true
for Cobol and Fortran: a huge installed base will be created.

However, if reliability really counts, I'd rather use Eiffel, a
comparatively small and elegant language, than punishing myself
with Ada. Eiffel can both be translated into C/C++ code or be
directly compiled into native code. Tower already did some work
integrating Eiffel with NeXTSTEP and I bet that would, given
sufficient interest, port rather easily to OSX(S).

Ada is unfortunately another one of these "designed by committee"
languages. No further comments... particularly since this is getting
somewhat off topic here. Anyone can do what they want, but I think
the idea that Ada will stir up a lot of enthusiasm around here is
an illusion. I think OO bindings to Scheme or CLOS, or a real
SmallTalk environment for Cocoa would attract far more attention
around here.
----------------------------------------------------------------------------------------------------------------------------------------------------

How does one define "state of the art" ? Let's not forget that computer
languages like human languages continues to evolve in order to survive
and maintain relevance.

And why would I care about Betrand Meyer's Eiffel and Xerox's SmallTalk
?

I have little interest in this time-consuming debate of C++ vs Ada. I
asked those provocative questions just to satisfy my curiosity.

I joined comp.lang.ada some 3 weeks ago and have been lurking since ...

Regards,

Wey Hua Siow
30th October 1999
Back to lurk mode !

Re: What Mac developers think of Ada !

[Ted Dennison]

In article <381A0466.2137859E@mbox5.singnet.com.sg>,
  ps750@mbox5.singnet.com.sg wrote:
> Date: Thu, 26 Aug 1999 04:29:48 -0400
> From: "Ronald C.F. Antony" <rcfa@cubiculum.com>
> Subject: Re: Coding Darwin in Ada 95
>
> > If Darwin is to be unique among the unixes, why not rewrite or
> recompile
> > the bulk of the Darwin OS (written in C++) in Ada 95 (high level OO
> > procedural-based language, ISO 8652:1995) instead of Objective C or
> C++
> > ?
>
> Because a) it's a lot of work, b) means everything would have to be
> reoptimized from scratch, c) C and Unix are like Strawberries and

a and b here are decent points, and are probably the real reason. The
rest of the post is pure hogwash.

--
T.E.D.


Sent via Deja.com http://www.deja.com/
Before you buy.

Re: What Mac developers think of Ada !

[Pascal Obry]

 
> In terms of portability Ada is beaten by C, Java, Cobol..., in terms of
> reusability by SmallTalk, ObjC, etc. and in terms of reliability by a
> slew of smaller languages. Ada is huge, and thus the likelyhood of
> having bugs in the compiler etc. are much higher than for a small, lean
> and mean language.

These are the most stupids comments I've ever read. The first points
are completly wrong and the latest point is just nonsense.

Ok, Ada is huge and there is maybe more chances to have bugs in the
compiler. But the high level features that you lack in other languages
you'll have to "emulate" them yourself in C, Java, ObjC... and here
you are going to introduce lot of bugs yourself... Except if you are
lot more experienced than the Ada compiler builders!

And it is far easier to send a bug report to your compiler vendor instead
of fightling with your own bugs!

I've not read the article after this point :-)

Pascal.

Re: What Mac developers think of Ada !

[David Starner]

On 30 Oct 1999 08:23:39 GMT, Pascal Obry <pascal_obry@csi.com> wrote:
>Ok, Ada is huge and there is maybe more chances to have bugs in the
>compiler. 
I'm not sure this is fair. Compared with the languages that were popular
in '83, sure, Ada was a little large. (C is a small language, and the
Pascals and BASICs of the time were small.) It's smaller than C++, currently
a popular language. The compiler frontend would be simpler than Fortran 90.
Java maybe fairly small, but the standard library is huge and growing.
And compared to implemented languages? Anyone take a look at GNU Pascal
recently? Visual Basic? 

--
David Starner - dstarner98@aasaa.ofe.org

Re: What Mac developers think of Ada !

[Preben Randhol]

dvdeug@x8b4e53cd. (David Starner) writes:

| On 30 Oct 1999 08:23:39 GMT, Pascal Obry <pascal_obry@csi.com> wrote:
| >Ok, Ada is huge and there is maybe more chances to have bugs in the
| >compiler. 
| I'm not sure this is fair. Compared with the languages that were popular
| in '83, sure, Ada was a little large. (C is a small language, and the
| Pascals and BASICs of the time were small.) It's smaller than C++, currently
| a popular language. The compiler frontend would be simpler than Fortran 90.
| Java maybe fairly small, but the standard library is huge and growing.
| And compared to implemented languages? Anyone take a look at GNU Pascal
| recently? Visual Basic? 

I agree.

C is a small language so you have to implement things that already are
in Ada. I think that the chance that there are bugs in those self made
C implementations is bigger than in the compiler for a well tested
language designed with these implementations.

Preben who hate that so many C programs SIGSEVS.

-- 
Preben Randhol                 Affliction is enamoured of thy parts, 
[randhol@pvv.org]              And thou art wedded to calamity. 
[http://www.pvv.org/~randhol/]                    -- W. Shakespeare 

Re: What Mac developers think of Ada !

[Nick Roberts]

Siow Wey Hua,

I applaud your sending in this question to the Darwin mailing list (and
I think many other on comp.lang.ada will too). Every time someone like
yourself asks awkward questions about why people use outdated languages
for outdated reasons helps the cause of improving software in the world,
even if just a little. 

And, because you are not in the Ada 'camp', as it were, your questioning
has more authority, in effect, than ours could. Please keep asking!

I can think of a few answers to the objections raised by those who
responded to your question. Please, by all means, put my responses here
to the mailing list.

==========

> b) means everything would have to be reoptimized from scratch, 

A dubious statement. Most of the 'optimizations' in question would carry
directly over in the translation. The remainder would probably be
outshone by the improvement in speed obtained simply by rewriting in
Ada.

> c) C and Unix are like Strawberries and Champagne, they belong
> together.

Historically, C and UNIX are, of course, intimately bound up with one
another. However, Ada 95 has excellent facilities for interfacing with C
(no worse than for C itself), largely obviating this objection.

> Further, strongly typed and dynamic OOP are for the most part at odds
> with
> each other. Ada may be able to replace C++, but it's hardly a fit
> replacement for the task ObjC is supposed to do.
> Your suggestion would be much more fit when we were talking about
> OpenVMS, than when talking about a Unix OS with an dynamic OOP
> environment.

Misses the point completely. There are large sections of BSD that are
not - and could not sensibly be - implemented with a dynamic OOP
language/environment. These are the parts that could and should be
rewritten in Ada. In addition, much of the infrastructure for a rich
dynamic OOP environment could also be written (or rewritten) in Ada. A
dynamic OOP language (preferably a well established one, like SmallTalk
for example) could then be used to provide the 'upper layers' of the
overall system (a scheme of which I, personally, thoroughly approve).

> In terms of portability Ada is beaten by C, Java, Cobol..., 

In terms of availability of compilers, Ada is beaten by C. But in terms
of portability of code written in a certain language, Ada beats C (hands
down). The same is true, to a lesser extent, of Ada versus Java and C++.
I don't think COBOL is really relevant to the issue.

> in terms of reusability by SmallTalk, ObjC, etc. 

Again, dynamic OOP languages are irrelevant. There is difference in
reusability between Objective C and Ada. However, Ada has the
acknowledged advantage of fully differentiating the namespace system
from the type system (which ObjC and C++ do not).

> and in terms of reliability by a slew of smaller languages. 

Which are all inadequate for the (entire) job *because* they are too
small. Using specialist languages for specialized parts of OS should not
be precluded. But for the bulk of it, a general purpose language is
necessary.

> Ada is huge, and thus the likelyhood of having bugs in the compiler
> etc. are much higher than for a small, lean and mean language.

A ludicrous statement, in view of the numerous bugs to be found in C and
(especially) ObjC and C++ compilers. Standard Ada 95, as a language, is
smaller
and simpler than standard C++ and much smaller than Java with its
(standard) libraries. Much of the greater size of Ada compared to C is
in the addition of functionality that is provided by library functions
in C (e.g. multi-tasking). Consider the multi-tasking support inherent
in the Ada 95 language: it puts C to shame, and is hardly irrelevant to
the application domain of a multi-tasking operating system!

> For application programming ADA may or may not be appropriate,
> depending on how much dynamism is required. Interfacing ADA to Cocoa
> wouldn't be exactly trivial...

Ada is primarily a systems programming language (more so than C, ObjC,
or C++),
and interfacing to Cocoa would be straightforward (but not
trivial, of course).

> Two words: Zero Mindshare.

Two words: closed mind.

==========

To recap, the arguments that languages such as SmallTalk are preferable
to Ada are
irrelevant; the parts of the operating system rewritten in Ada would be
100% complementary to the parts that would be written in such languages.

One of the respondents seemed to think that Objective C has some kind of
dynamism that Ada doesn't. This is not true. Both are static (compiled)
languages capable of dynamic polymorphism.

I would suggest you reiterate the main advantages of Ada: that the Ada
language nurtures the development of more reliable, maintainable, and
reusable code than C, ObjC, C++, or Java; that, in general, code written
in the Ada
language is certain to be more portable than that written
in C, ObjC, C++, or Java; that Ada's emphasis on well-defined interfaces
between modules is particularly relevant to the Open Source ('bazaar')
development process; Ada is purpose-designed as a systems programming
language especially suited to the development of large software.

Of course, I am myself (with others) writing an operating system in Ada.
Unfortunately, this is a 'hobby' project, with no real source of funds,
and will therefore inevitably be slow-running and small in scope. It
would be wonderful for
a project with the resources of a giant corporation (like Apple) behind
it to opt for Ada in
the development of an operating system.

-- 
Nick Roberts
Computer Consultant (UK)
http://www.callnetuk.com/home/nickroberts
http://www.adapower.com/lab/adaos

Re: What Mac developers think of Ada !

[Michael Smith]

Well said and thanks.  It saves me the trouble of responding

Nick Roberts wrote:

> Siow Wey Hua,
>
> I applaud your sending in this question to the Darwin mailing list (and
> I think many other on comp.lang.ada will too). Every time someone like
> yourself asks awkward questions about why people use outdated languages
> for outdated reasons helps the cause of improving software in the world,
> even if just a little.
>
> And, because you are not in the Ada 'camp', as it were, your questioning
> has more authority, in effect, than ours could. Please keep asking!
>
> I can think of a few answers to the objections raised by those who
> responded to your question. Please, by all means, put my responses here
> to the mailing list.
>
> ==========
>
> > b) means everything would have to be reoptimized from scratch,
>
> A dubious statement. Most of the 'optimizations' in question would carry
> directly over in the translation. The remainder would probably be
> outshone by the improvement in speed obtained simply by rewriting in
> Ada.
>
> > c) C and Unix are like Strawberries and Champagne, they belong
> > together.
>
> Historically, C and UNIX are, of course, intimately bound up with one
> another. However, Ada 95 has excellent facilities for interfacing with C
> (no worse than for C itself), largely obviating this objection.
>
> > Further, strongly typed and dynamic OOP are for the most part at odds
> > with
> > each other. Ada may be able to replace C++, but it's hardly a fit
> > replacement for the task ObjC is supposed to do.
> > Your suggestion would be much more fit when we were talking about
> > OpenVMS, than when talking about a Unix OS with an dynamic OOP
> > environment.
>
> Misses the point completely. There are large sections of BSD that are
> not - and could not sensibly be - implemented with a dynamic OOP
> language/environment. These are the parts that could and should be
> rewritten in Ada. In addition, much of the infrastructure for a rich
> dynamic OOP environment could also be written (or rewritten) in Ada. A
> dynamic OOP language (preferably a well established one, like SmallTalk
> for example) could then be used to provide the 'upper layers' of the
> overall system (a scheme of which I, personally, thoroughly approve).
>
> > In terms of portability Ada is beaten by C, Java, Cobol...,
>
> In terms of availability of compilers, Ada is beaten by C. But in terms
> of portability of code written in a certain language, Ada beats C (hands
> down). The same is true, to a lesser extent, of Ada versus Java and C++.
> I don't think COBOL is really relevant to the issue.
>
> > in terms of reusability by SmallTalk, ObjC, etc.
>
> Again, dynamic OOP languages are irrelevant. There is difference in
> reusability between Objective C and Ada. However, Ada has the
> acknowledged advantage of fully differentiating the namespace system
> from the type system (which ObjC and C++ do not).
>
> > and in terms of reliability by a slew of smaller languages.
>
> Which are all inadequate for the (entire) job *because* they are too
> small. Using specialist languages for specialized parts of OS should not
> be precluded. But for the bulk of it, a general purpose language is
> necessary.
>
> > Ada is huge, and thus the likelyhood of having bugs in the compiler
> > etc. are much higher than for a small, lean and mean language.
>
> A ludicrous statement, in view of the numerous bugs to be found in C and
> (especially) ObjC and C++ compilers. Standard Ada 95, as a language, is
> smaller
> and simpler than standard C++ and much smaller than Java with its
> (standard) libraries. Much of the greater size of Ada compared to C is
> in the addition of functionality that is provided by library functions
> in C (e.g. multi-tasking). Consider the multi-tasking support inherent
> in the Ada 95 language: it puts C to shame, and is hardly irrelevant to
> the application domain of a multi-tasking operating system!
>
> > For application programming ADA may or may not be appropriate,
> > depending on how much dynamism is required. Interfacing ADA to Cocoa
> > wouldn't be exactly trivial...
>
> Ada is primarily a systems programming language (more so than C, ObjC,
> or C++),
> and interfacing to Cocoa would be straightforward (but not
> trivial, of course).
>
> > Two words: Zero Mindshare.
>
> Two words: closed mind.
>
> ==========
>
> To recap, the arguments that languages such as SmallTalk are preferable
> to Ada are
> irrelevant; the parts of the operating system rewritten in Ada would be
> 100% complementary to the parts that would be written in such languages.
>
> One of the respondents seemed to think that Objective C has some kind of
> dynamism that Ada doesn't. This is not true. Both are static (compiled)
> languages capable of dynamic polymorphism.
>
> I would suggest you reiterate the main advantages of Ada: that the Ada
> language nurtures the development of more reliable, maintainable, and
> reusable code than C, ObjC, C++, or Java; that, in general, code written
> in the Ada
> language is certain to be more portable than that written
> in C, ObjC, C++, or Java; that Ada's emphasis on well-defined interfaces
> between modules is particularly relevant to the Open Source ('bazaar')
> development process; Ada is purpose-designed as a systems programming
> language especially suited to the development of large software.
>
> Of course, I am myself (with others) writing an operating system in Ada.
> Unfortunately, this is a 'hobby' project, with no real source of funds,
> and will therefore inevitably be slow-running and small in scope. It
> would be wonderful for
> a project with the resources of a giant corporation (like Apple) behind
> it to opt for Ada in
> the development of an operating system.
>
> --
> Nick Roberts
> Computer Consultant (UK)
> http://www.callnetuk.com/home/nickroberts
> http://www.adapower.com/lab/adaos

-- BTW -- Take out the "noone." to reply

Re: What Mac developers think of Ada !

[Robert Dewar]

In article <381E49FB.6CBD7050@home.com>,
  alphasoft@noone.home.com wrote:

> Well said and thanks.  It saves me the trouble of responding

Not exactly the highest content message we have seen this
morning, and then proceeded to quote several hundred lines
intact.

Please, please can people be more careful in quoting full
messages. It is a prevalent disease throughout usenet, and
apparently the result of a flood of relatively new users
who either don't know the conventions or (hard to believe
but true in some cases) don't know how to do partial quoting.

Just think, if I followed this practice, then this message
would have the same several hundred lines attached to it!!

Thanks for thinking about this when you post!


Sent via Deja.com http://www.deja.com/
Before you buy.

Excessive quoting (was: What Mac developers think of Ada !)

[Ted Dennison]

In article <7vmjde$olr$1@nnrp1.deja.com>,
  Robert Dewar <robert_dewar@my-deja.com> wrote:

> messages. It is a prevalent disease throughout usenet, and
> apparently the result of a flood of relatively new users
> who either don't know the conventions or (hard to believe
> but true in some cases) don't know how to do partial quoting.

It is enough to make one pine for the days of "fascist" newsreaders that
refused to post anything with more quoted material than new text or with
a signature more than 3 lines long.

These days I don't think newsreader authors care at all about
helping Usenet itself. For instance, with the Deja interface, the entry
window is so small that its quite easy to accidentally post a ton of
irrelevent quoted text (sigh).

--
T.E.D.


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Before you buy.

Re: Excessive quoting (was: What Mac developers think of Ada !)

[Florian Weimer]

Ted Dennison <dennison@telepath.com> writes:

> These days I don't think newsreader authors care at all about
> helping Usenet itself. For instance, with the Deja interface, the entry
> window is so small that its quite easy to accidentally post a ton of
> irrelevent quoted text (sigh).

And Deja users tend to post their articles multiple times. ;)