I am delighted to discover what seems to be a relatively lively newsgroup!

I used to program Fortran at Uni in the late 1980s. F77 on VAX/VMS,
mainly. I was fairly _au fait_ with it.

I haven't really coded in decades and I keep pondering trying to get
back into it.

I have looked at various modern languages but find all the OOPS and so
on confusing and unnecessary for small, hobbyist stuff.

For a non-professional, is modern Fortran so very different from F77
that it would be akin to learning a new language, or do folks think it
might be relatively easy to update my knowledge and pick it up again?

Is there much in the way of supporting libraries, or is Fortran only
used for numerical stuff these days?

--
Liam P. ~ Prague, Czechia ~ liamproven on yahoo UK and AOL

On Tuesday, April 5, 2022 at 10:51:33 AM UTC-4, Liam Proven wrote:

> I am delighted to discover what seems to be a relatively lively newsgroup!
> ..

@Liam Proven,

Welcome! Please also try Fortran Discourse where you might value in engagement with other readers using Fortran syntax-highlighted posting and reading for code snippets, file attachments, URL links that highlight headlines (and summary), etc.
https://fortran-lang.discourse.group/

And at Fortran Discourse, you will find regular visitors who are now starting to working on Fortran "standard' libraries:
https://github.com/fortran-lang/stdlib

and those developing Fortran course material like a 25 year-old scientist:
https://fortran-lang.discourse.group/t/literature-for-modern-fortran-lectures/3084/38

And so forth.

As to whether "modern Fortran so very different from F77 that it would be akin to learning a new language," the answer will really depend on what you are trying to! If the sequential procedural approach suits well for the applications you have in mind, you will mind modern Fortran is FORTRAN 77 but without the limitations i.e., modern Fortran supports free-form source, you can have longer variable names and lines, and so forth. But you should explore for yourself and post your discoveries online!

Cheers,

Le 05/04/2022 à 16:51, Liam Proven a écrit :
> I am delighted to discover what seems to be a relatively lively newsgroup!
>
> I used to program Fortran at Uni in the late 1980s. F77 on VAX/VMS,
> mainly. I was fairly _au fait_ with it.
>
> I haven't really coded in decades and I keep pondering trying to get
> back into it.
>
> I have looked at various modern languages but find all the OOPS and so
> on confusing and unnecessary for small, hobbyist stuff.
>
> For a non-professional, is modern Fortran so very different from F77
> that it would be akin to learning a new language, or do folks think it
> might be relatively easy to update my knowledge and pick it up again?
>
> Is there much in the way of supporting libraries, or is Fortran only
> used for numerical stuff these days?
>
I was using FORTRAN 77 as I was a student. Now, I am retired : in my
professional life, I have used, the version 90, 95, and 2003. And the
list is not complete.
The rigidity of version 77 is forgotten now.

bruno M.

On Tuesday, April 5, 2022 at 10:51:33 AM UTC-4, Liam Proven wrote:
> I am delighted to discover what seems to be a relatively lively newsgroup!
>
> I used to program Fortran at Uni in the late 1980s. F77 on VAX/VMS,
> mainly. I was fairly _au fait_ with it.
>
> I haven't really coded in decades and I keep pondering trying to get
> back into it.
>
> I have looked at various modern languages but find all the OOPS and so
> on confusing and unnecessary for small, hobbyist stuff.
>
> For a non-professional, is modern Fortran so very different from F77
> that it would be akin to learning a new language, or do folks think it
> might be relatively easy to update my knowledge and pick it up again?
>
> Is there much in the way of supporting libraries, or is Fortran only
> used for numerical stuff these days?
>
> --
> Liam P. ~ Prague, Czechia ~ liamproven on yahoo UK and AOL

I second the advice of FortranFan. At the Fortran Wiki https://fortranwiki.org/fortran/show/Tutorials
you can search "77" to find several tutorials on Fortran 90 or 95 aimed at Fortran 77 programmers.

Liam Proven <lproven+un@hotmail.com> schrieb:
> I am delighted to discover what seems to be a relatively lively newsgroup!
>
> I used to program Fortran at Uni in the late 1980s. F77 on VAX/VMS,
> mainly. I was fairly _au fait_ with it.
>
> I haven't really coded in decades and I keep pondering trying to get
> back into it.
>
> I have looked at various modern languages but find all the OOPS and so
> on confusing and unnecessary for small, hobbyist stuff.

I agree :-)

>
> For a non-professional, is modern Fortran so very different from F77
> that it would be akin to learning a new language, or do folks think it
> might be relatively easy to update my knowledge and pick it up again?

A nice thing is that old F77 codes still work, so you do not
really have to change anything. However, you would miss out on
some really conventient features: Interface checking via modules,
array bounds that are passed with the arguments, array expressions,
dynamic memory via arrays that are deallocated when they go out
of scope, and array expressions. Plus, if your code uses global
variables, you can put them type-safely into modules instead of
COMMON blocks.

https://en.wikipedia.org/wiki/Fortran_95_language_features has a
very nice feature list of Fortran 95 written by Michael Metcalf.
The only thing it misses of the list above are allocatable arrays,
which came later than Fortran 95.

On Wednesday, April 6, 2022 at 6:44:21 AM UTC-4, Thomas Koenig wrote:
> https://en.wikipedia.org/wiki/Fortran_95_language_features has a
> very nice feature list of Fortran 95 written by Michael Metcalf.
> The only thing it misses of the list above are allocatable arrays,
> which came later than Fortran 95.

Fortran 90 and 95 had allocatable arrays, but in Fortran 2003 it became possible
to use them in more contexts, such as function and subroutine arguments,
function results, and components of derived types.

"Liam Proven" wrote in message news:t2hl1h$e7g$1@dont-email.me...

> I am delighted to discover what seems to be a relatively lively newsgroup!

> I used to program Fortran at Uni in the late 1980s. F77 on VAX/VMS,
> mainly. I was fairly _au fait_ with it.

> I haven't really coded in decades and I keep pondering trying to get back
> into it.

> I have looked at various modern languages but find all the OOPS and so on
> confusing and unnecessary for small, hobbyist stuff.

> For a non-professional, is modern Fortran so very different from F77 that
> it would be akin to learning a new language, or do folks think it might be
> relatively easy to update my knowledge and pick it up again?

> Is there much in the way of supporting libraries, or is Fortran only used
> for numerical stuff these days?

Standard F77 should pretty much work in F2003 and even more recent.
One big attraction to modern Fortran as I see it is that it provides
standard solutions to some of the big problems that F77 programs
would have to jump through major hoops to work around, like
dynamic memory and interfacing with other languages or even
other Fortran compilers.

Fortran 2003 more or less stole support from many libraries when
it provided the capability to write out an interface for a C function
in Fortran. Lacks some interoperability features such as varargs
(MAC OS) or unions (Windows) but a lot of stuff is there.

On 4/6/22 8:11 AM, Beliavsky wrote:
> On Wednesday, April 6, 2022 at 6:44:21 AM UTC-4, Thomas Koenig wrote:
>> https://en.wikipedia.org/wiki/Fortran_95_language_features has a
>> very nice feature list of Fortran 95 written by Michael Metcalf.
>> The only thing it misses of the list above are allocatable arrays,
>> which came later than Fortran 95.
>
> Fortran 90 and 95 had allocatable arrays, but in Fortran 2003 it became possible
> to use them in more contexts, such as function and subroutine arguments,
> function results, and components of derived types.

The timing of those features was unfortunate. The Allocatable Technical
Report that defined them was published at the same time that f95 was
released (about 1998). But because those features were not in the ISO
language, they were not included in several of the popular f95 compilers
for several years. Finally in f2003 they were all incorporated into the
standard. So for those of us who were attempting to write portable code,
we could not use those features during that approximately eight year
period. It was frustrating because they are some very nice features to
have available.

$.02 -Ron Shepard

On Tuesday, April 5, 2022 at 7:51:33 AM UTC-7, Liam Proven wrote:
> I am delighted to discover what seems to be a relatively lively newsgroup!
> I used to program Fortran at Uni in the late 1980s. F77 on VAX/VMS,
> mainly. I was fairly _au fait_ with it.
> I haven't really coded in decades and I keep pondering trying to get
> back into it.
> I have looked at various modern languages but find all the OOPS and so
> on confusing and unnecessary for small, hobbyist stuff.
> For a non-professional, is modern Fortran so very different from F77
> that it would be akin to learning a new language, or do folks think it
> might be relatively easy to update my knowledge and pick it up again?
Modern Fortran is pretty different, but just about all the features
in Fortran 77 are still there. So, you can start with what you knew
before, and slowly learn and add newer features to your programs.

One of the new features is free-form, which removes the need to
start in column 7 (or more), and also changes the way continuation
lines work. Maybe surprising to some, all the new features work
in the old fixed-form.

A year or so ago, I had running both IBM's ECAP, from the
early to mid 1960's, and SPICE 2g6 from about 1983.

Both took a little work to get running, where they use non-standard
features, or otherwise need fixing.

You can learn about new features as slow or fast as you like.

And with free compilers easily available, it is a nice time to learn!

On 05/04/2022 17:54, FortranFan wrote:
>
> Welcome!

:-)

> Please also try Fortran Discourse where you might value in engagement
with other readers using Fortran syntax-highlighted posting and reading
for code snippets, file attachments, URL links that highlight headlines
(and summary), etc.
> https://fortran-lang.discourse.group/

I have a Discourse account, but to be honest, I do not like web fora
much. That's why I have returned to Usenet again. It and mailing lists
are comfortable like an old slipper.

>
> As to whether "modern Fortran so very different from F77 that it would be akin to learning a new language," the answer will really depend on what you are trying to! If the sequential procedural approach suits well for the applications you have in mind, you will mind modern Fortran is FORTRAN 77 but without the limitations i.e., modern Fortran supports free-form source, you can have longer variable names and lines, and so forth. But you should explore for yourself and post your discoveries online!

Interesting... fair enough...

--
Liam Proven ~ Prague, Czechia
lproven+es@hotmail.com
(or liamproven on either AOL or Yahoo UK)

On 06/04/2022 12:44, Thomas Koenig wrote:
>>
>> I have looked at various modern languages but find all the OOPS and so
>> on confusing and unnecessary for small, hobbyist stuff.
>
> I agree :-)

Oh good. Glad to hear it's not just me.

> A nice thing is that old F77 codes still work, so you do not
> really have to change anything. However, you would miss out on
> some really conventient features: Interface checking via modules,
> array bounds that are passed with the arguments, array expressions,
> dynamic memory via arrays that are deallocated when they go out
> of scope, and array expressions. Plus, if your code uses global
> variables, you can put them type-safely into modules instead of
> COMMON blocks.
>
> https://en.wikipedia.org/wiki/Fortran_95_language_features has a
> very nice feature list of Fortran 95 written by Michael Metcalf.
> The only thing it misses of the list above are allocatable arrays,
> which came later than Fortran 95.

Interesting info... thank you.

--
Liam Proven ~ Prague, Czechia
lproven+es@hotmail.com
(or liamproven on either AOL or Yahoo UK)

Liam Proven <lproven+un@hotmail.com> wrote:
> I am delighted to discover what seems to be a relatively
> lively newsgroup!

Same here

<snip>

> I have looked at various modern languages but find all the OOPS and
> so on confusing and unnecessary for small, hobbyist stuff.

Same here, very confusing and in fact I do not see the point
of OO. Luckily I never had to deal with it professionally.

> For a non-professional, is modern Fortran so very different from F77
> that it would be akin to learning a new language, or do folks think it
> might be relatively easy to update my knowledge and pick it up again?

I also have been playing around with Fortran (gfortran) with
an eye to relearn it, hope to be retiring soon and this is
one thing that will keep me occupied. Like you, I last used
F77 and ended up moving on to other languages in the 80s.

<snip>

John

--
[t]csh(1) - "An elegant shell, for a more... civilized age."
- Paraphrasing Star Wars

Le 03/05/2022 à 22:59, John McCue a écrit :
> Liam Proven <lproven+un@hotmail.com> wrote:
>> I am delighted to discover what seems to be a relatively
>> lively newsgroup!
>
> Same here
>
> <snip>
>
>> I have looked at various modern languages but find all the OOPS and
>> so on confusing and unnecessary for small, hobbyist stuff.
>
> Same here, very confusing and in fact I do not see the point
> of OO. Luckily I never had to deal with it professionally.
>
>> For a non-professional, is modern Fortran so very different from F77
>> that it would be akin to learning a new language, or do folks think it
>> might be relatively easy to update my knowledge and pick it up again?
>
> I also have been playing around with Fortran (gfortran) with
> an eye to relearn it, hope to be retiring soon and this is
> one thing that will keep me occupied. Like you, I last used
> F77 and ended up moving on to other languages in the 80s.
>
> <snip>
>
> John
>
No more need to use gfortran, the onePAI of Intel works on all platforms
( compilers and many tools are free to use)

My lenovo T430 with Linux works fine

On 5/4/22 8:24 AM, bruno wrote:
[...]
> No more need to use gfortran, the onePAI of Intel works on all platforms
> ( compilers and many tools are free to use)

I think it only works on intel and AMD hardware and on linux and windows
software. Their classic compiler works also on intel+MacOS. At least the
last I checked, it did not work on IBM PowerPC hardware or on Apple ARM
hardware, and of course there is a lot of legacy hardware and software
where it does not run. Gfortran does work on many of these other
combinations of hardware and software.

$.02 -Ron Shepard

John McCue <jmccue@magnetar.hsd1.ma.comcast.net> writes:
>Same here, very confusing and in fact I do not see the point
>of OO.

The point of OOP is to be able to easily add new data types
without having to modify existing code.

For example, in Python, there is a "print" procedure that
can print objects of many built-in data types like "string"
and "int".

OOP allows one to add a new data type, for example, "matrix",
and then "print" will be able to print matrices after only
code for "matrix" was written (added) - /without/ a need to
actually modify "print".

On 5/4/2022 11:34 AM, Stefan Ram wrote:
> John McCue <jmccue@magnetar.hsd1.ma.comcast.net> writes:
>> Same here, very confusing and in fact I do not see the point
>> of OO.
>
> The point of OOP is to be able to easily add new data types
> without having to modify existing code.
>
> For example, in Python, there is a "print" procedure that
> can print objects of many built-in data types like "string"
> and "int".
>
> OOP allows one to add a new data type, for example, "matrix",
> and then "print" will be able to print matrices after only
> code for "matrix" was written (added) - /without/ a need to
> actually modify "print".
>
>
Ah, terminology. To me a "type" is an intrinsic thing. When you define
a "derived type", you're creating a "container" (structure) of intrinsic
types. Is that "container" then a type? To me, no, it's a container,
for convenience. (so I would not have used the terminology derived
type, but "structure" or "container" or ...

On 04/05/2022 18:34, Stefan Ram wrote:
>
> The point of OOP is to be able to easily add new data types
> without having to modify existing code.

That seems a little sweeping.

It seems to me that OOP has nearly as many different purposes as there
are people using it.

My cynical suspicion is that Rob Pike (of Plan 9 and Go fame) nailed it
with his line:

"Object-oriented design is the Roman numerals of computing."

I suspect (but do not know, and cannot prove) that it is immensely
powerful in languages originally built around it, such as Smalltalk and
Self.

When it was subsequently bolted on to pre-existing languages, from BASIC
to Fortran to Pascal, it is rather less so.

--
Liam Proven ~ Prague, Czechia
lproven+es@hotmail.com
(or liamproven on either AOL or Yahoo UK)

Liam Proven wrote:

> On 04/05/2022 18:34, Stefan Ram wrote:
> >
> > The point of OOP is to be able to easily add new data types
> > without having to modify existing code.
>
> That seems a little sweeping.
>
> It seems to me that OOP has nearly as many different purposes as
> there are people using it.
>
> My cynical suspicion is that Rob Pike (of Plan 9 and Go fame) nailed
> it with his line:
>
> "Object-oriented design is the Roman numerals of computing."
>
> I suspect (but do not know, and cannot prove) that it is immensely
> powerful in languages originally built around it, such as Smalltalk
> and Self.
>
> When it was subsequently bolted on to pre-existing languages, from
> BASIC to Fortran to Pascal, it is rather less so.

I partly agree with this, except that to me OOP has little to do with
the programming language being used but is rather abut doing
pre-programming thinking ... thinking about what parts of a system of
sub-programs will need access to what subsets of information. When
employed, I once used OOP principles as a pre+cursor to developing a
complicated program written in Fortran 77.

Basically, OOP provides help with the initial step when faced with a
new task of: "where do I begin?"

On Thursday, May 5, 2022 at 5:28:58 AM UTC-4, Liam Proven wrote:
> On 04/05/2022 18:34, Stefan Ram wrote:
> >
> > The point of OOP is to be able to easily add new data types
> > without having to modify existing code.
> That seems a little sweeping.
>
> It seems to me that OOP has nearly as many different purposes as there
> are people using it.
>
> My cynical suspicion is that Rob Pike (of Plan 9 and Go fame) nailed it
> with his line:
>
> "Object-oriented design is the Roman numerals of computing."
>
> I suspect (but do not know, and cannot prove) that it is immensely
> powerful in languages originally built around it, such as Smalltalk and
> Self.
>
> When it was subsequently bolted on to pre-existing languages, from BASIC
> to Fortran to Pascal, it is rather less so.
> --
> Liam Proven ~ Prague, Czechia
> lprov...@hotmail.com
> (or liamproven on either AOL or Yahoo UK)

Not every Fortran program needs to use inheritance, and it's not clear to me that
type-bound procedures have a better syntax than procedures with derived type arguments.
But I think OOP can reduce duplication when the same procedures are applicable to
multiple related derived types, having created such duplicates when sticking to Fortran 95
derived types.

On Thursday, May 5, 2022 at 5:28:58 AM UTC-4, Liam Proven wrote:

> On 04/05/2022 18:34, Stefan Ram wrote:
> >
> > The point of OOP is to be able to easily add new data types
> > without having to modify existing code.
> That seems a little sweeping.
>
> It seems to me that OOP has nearly as many different purposes as there
> are people using it.
>
> My cynical suspicion is that Rob Pike (of Plan 9 and Go fame) nailed it
> with his line:
>
> "Object-oriented design is the Roman numerals of computing."
>
> I suspect (but do not know, and cannot prove) that it is immensely
> powerful in languages originally built around it, such as Smalltalk and
> Self.
>
> When it was subsequently bolted on to pre-existing languages, from BASIC
> to Fortran to Pascal, it is rather less so.
> --
> Liam Proven ~ Prague, Czechia
> lprov...@hotmail.com
> (or liamproven on either AOL or Yahoo UK)

@Liam Proven,

Please - if you are coming to Fortran from the days of FORTRAN 77 and related earlier dialects - there is no need to get hung up on OOP.

There is a lot in the current standard other than OOP to work with if you so choose, or you can even stick to your FORTRAN style of coding if you so wish.

Move on, and please just know most of what you suspect about OOP is WRONG.

FortranFan <parekhvs@gmail.com> writes:
>On Thursday, May 5, 2022 at 5:28:58 AM UTC-4, Liam Proven wrote:
....
>>I suspect (but do not know, and cannot prove) that it is immensely
>>powerful in languages originally built around it, such as Smalltalk and
>>Self.
....
>Move on, and please just know most of what you suspect about OOP is WRONG.

There might be some truth in at least one thing Liam wrote!

In 2003, I became aware of the fact that Alan Kay, the man
who coined the term "object-oriented programming" in 1967
(or in the temporal proximity of this year), never has given
a definition for it. I asked him via e-mail, and he kindly
responded. In that e-mail he also wrote something to the effect
that for him only Smalltalk allows object-oriented programming.
(On another occasion, he also said, "I invented the term Object-
Oriented and I can tell you I did not have C++ in mind.".) So,
I think that this point of view by Alan Kay is similar to what
Liam wrote about Smalltalk!

So, what did Alan Kay write to me in 2003? Here's the crucial excerpt:

|OOP to me means only messaging, local retention and protection and
|hiding of state-process, and extreme late-binding of all things. It
|can be done in Smalltalk and in LISP. There are possibly other
|systems in which this is possible, but I'm not aware of them.
Alan Kay, 2003

. I should add that the deepest insight I gained into what is the
actual point of OOP (as I wrote in my previous post in this thread)
I got from the writings of Robert C. Martin who clarified that
OOP makes it easy to add new types but hard to add new operations,
while procedural programming makes it easy to add new operations,
but hard to add new types.

|Procedural code (code using data structures) makes it easy to
|add new functions without changing the existing data
|structures. OO code, on the other hand, makes it easy to add
|new classes without changing existing functions.
Robert Cecil Martin

|Procedural code makes it hard to add new data structures
|because all the functions must change. OO code makes it hard
|to add new functions because all the classes must change.
Robert Cecil Martin

When one first reads this, it might not be obvious why this
is so spot on, but one can find this quotation in the book
"Clean Code" by Robert C. Martin and read more explanations
about it there.

Objects with data abstraction can already be found in CLU by
Barbara Liskov. But this is not yet OOP. The crucial feature
OOP adds to this is polymorphism ("late binding").

On 05/05/2022 17:22, Stefan Ram wrote:
>
> There might be some truth in at least one thing Liam wrote!

I do try. :-D

> So, what did Alan Kay write to me in 2003? Here's the crucial excerpt:
>
> |OOP to me means only messaging, local retention and protection and
> |hiding of state-process, and extreme late-binding of all things. It
> |can be done in Smalltalk and in LISP. There are possibly other
> |systems in which this is possible, but I'm not aware of them.
> Alan Kay, 2003

Aha! So your email is the origin of this Quora thread?

https://www.quora.com/What-does-Alan-Kay-mean-when-he-said-OOP-to-me-means-only-messaging-local-retention-and-protection-and-hiding-of-state-process-and-extreme-late-binding-of-all-things-It-can-be-done-in-Smalltalk-and-in-LISP

How wonderful. Small world. Thank you for that!

--
Liam Proven ~ Prague, Czechia
lproven+es@hotmail.com
(or liamproven on either AOL or Yahoo UK)

On 05/05/2022 15:47, FortranFan wrote:

> Please - if you are coming to Fortran from the days of FORTRAN 77 and related earlier dialects - there is no need to get hung up on OOP.
>
> There is a lot in the current standard other than OOP to work with if you so choose, or you can even stick to your FORTRAN style of coding if you so wish.
>
> Move on, and please just know most of what you suspect about OOP is WRONG.

That is good to hear. Thanks for the reassurance.

--
Liam Proven ~ Prague, Czechia
lproven+es@hotmail.com
(or liamproven on either AOL or Yahoo UK)

On 5/5/2022 10:22 AM, Stefan Ram wrote:
> FortranFan <parekhvs@gmail.com> writes:
>> On Thursday, May 5, 2022 at 5:28:58 AM UTC-4, Liam Proven wrote:
> ...
>>> I suspect (but do not know, and cannot prove) that it is immensely
>>> powerful in languages originally built around it, such as Smalltalk and
>>> Self.
> ...
>> Move on, and please just know most of what you suspect about OOP is WRONG.
>
> There might be some truth in at least one thing Liam wrote!
>
> In 2003, I became aware of the fact that Alan Kay, the man
> who coined the term "object-oriented programming" in 1967
> (or in the temporal proximity of this year), never has given
> a definition for it. I asked him via e-mail, and he kindly
> responded. In that e-mail he also wrote something to the effect
> that for him only Smalltalk allows object-oriented programming.
> (On another occasion, he also said, "I invented the term Object-
> Oriented and I can tell you I did not have C++ in mind.".) So,
> I think that this point of view by Alan Kay is similar to what
> Liam wrote about Smalltalk!
>
> So, what did Alan Kay write to me in 2003? Here's the crucial excerpt:
>
> |OOP to me means only messaging, local retention and protection and
> |hiding of state-process, and extreme late-binding of all things. It
> |can be done in Smalltalk and in LISP. There are possibly other
> |systems in which this is possible, but I'm not aware of them.
> Alan Kay, 2003
>
> . I should add that the deepest insight I gained into what is the
> actual point of OOP (as I wrote in my previous post in this thread)
> I got from the writings of Robert C. Martin who clarified that
> OOP makes it easy to add new types but hard to add new operations,
> while procedural programming makes it easy to add new operations,
> but hard to add new types.
>
> |Procedural code (code using data structures) makes it easy to
> |add new functions without changing the existing data
> |structures. OO code, on the other hand, makes it easy to add
> |new classes without changing existing functions.
> Robert Cecil Martin
>
> |Procedural code makes it hard to add new data structures
> |because all the functions must change. OO code makes it hard
> |to add new functions because all the classes must change.
> Robert Cecil Martin
>
> When one first reads this, it might not be obvious why this
> is so spot on, but one can find this quotation in the book
> "Clean Code" by Robert C. Martin and read more explanations
> about it there.
>
> Objects with data abstraction can already be found in CLU by
> Barbara Liskov. But this is not yet OOP. The crucial feature
> OOP adds to this is polymorphism ("late binding").

I converted my 240,000 line Win16 Smalltalk app to a 350,000 line Win32
C++ app in 2002. The problem with Smalltalk is that it is 100X slower
than C++ (I timed it !) and the late binding. Plus my Smalltalk
compiler and linker did not make the transition from Win16 to Win32.
The author gave me the Smalltalk compiler and runtime assembly language
but I could not port it to Win32 in a reasonable amount of time so I
ported my app.

If you passed an object to a method and that object did not have a
method for inverting it (or something like that) that was called in the
method, the app crashed. You had to make sure that every object
potentially being used in a method had every method that was called in
the method. Very painful in the long run. C++ ensures that late bound
method calls in a method always have a corresponding method in their
object inheritance, very nice. I use late binding all over my C++ code,
works well.

I do miss the heterogeneous collections in Smalltalk. That was an
incredibly cool feature. That was the hardest part of the conversion to
C++ as we converted all those to homogeneous collections so we had to
rework some of the object classes.

Lynn