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Groups > comp.lang.forth > #34150

Re: uninitialized and implicitly initialized locals

From Andrew Haley <andrew29@littlepinkcloud.invalid>
Subject Re: uninitialized and implicitly initialized locals
Newsgroups comp.lang.forth
References (6 earlier) <2014Oct16.141939@mips.complang.tuwien.ac.at> <GNKdnUPWhZo1RN3JnZ2dnUU7-eOdnZ2d@supernews.com> <2014Oct18.145533@mips.complang.tuwien.ac.at> <cNKdnXYe2Y48Mt_JnZ2dnUU7-TudnZ2d@supernews.com> <2014Oct20.144848@mips.complang.tuwien.ac.at>
Message-ID <8tydnedGaJWeIdHJnZ2dnUU7-SWdnZ2d@supernews.com> (permalink)
Date 2014-10-26 04:16 -0500

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Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:
> Andrew Haley <andrew29@littlepinkcloud.invalid> writes:
>>Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:
>>> Andrew Haley <andrew29@littlepinkcloud.invalid> writes:
>>>>Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:
>>>>> Andrew Haley <andrew29@littlepinkcloud.invalid> writes:
>>>>>>Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:
>>>>>>> Andrew Haley <andrew29@littlepinkcloud.invalid> writes:
>>> 
>>>>>>We've got too much of it already and the Basic Principle of Forth is
>>>>>>"Keep it simple!":
>>> ...
>>>>>>"It is very hard to apply. All the pressures, internal and external,
>>>>>>conspire to add features to your program. After all, it only takes a
>>>>>>half-dozen instructions, so why not? The only opposing pressure is the
>>>>>>Basic Principle, and if you ignore it, there is no opposing pressure."
>>>>>>[1]
>>> ...
>>>>> Sure, if you follow it, you arrive at colorForth, I guess.  I don't
>>>>> arrive at colorForth in my Forth work, so I obviously don't agree with
>>>>> it. 
>>>>
>>>>No, that does not follow.  The Basic Principle also led to miniForth,
>>>>polyFORTH, and (indirectly) fig-FORTH and all its derivatives.  It
>>>>does not only lead to one solution.
> 
> I doubt that Chuck Moore sees all of these systems as equally good and
> valid solutions.  It's a progression: First he did Forth, the
> mini-Forth, then microForth, then cmForth, then machineForth, and now
> colorForth.  At every step he gave preference to his new design over
> his old design, and he never returned to miniForth or PolyForth.  He
> did abandon the approach of leaving the Forth compiler/text
> interpreter away completely (OKAD).

Sure, that's probably so, but so what?  Forth is the product of many
people's efforts and opinions.

>>> 1) Capability: Not everyone is as capable as Charles Moore, Ken
>>> Thompson, or Jochen Liedtke at finding simple solutions.
>>
>>True, but between us we might be able to get somewhere close, but IMO
>>we surely won't if we ignore the principle.
> 
> Ok, but my point was not to ignore simplicity.  Instead, I
> contradicted the claim that you need an axiomatic Basic Principle to
> keep things simple, because there is supposedly no other force acting
> against complexity.

Perhaps.  It is certainly true that Forth takes a pretty extreme
position on the complexity - features line, and its unique character
is due to that position.  It does mean that new language features
should have a high bar to jump.

>>In once place I worked we use to call some features "WIBNIs", where a
>>WIBNI was short for "Wouldn't It Be Nice If..."  WIBNIs should be
>>avoided like the plague; features should be added if they're *needed*.
>>And multiple locals declarations, even if occasionally nice to have,
>>are not necessary.
> 
> N>R and NR> are not necessary, either, and I don't consider them nice
> to have.  Your reaction: "what's not to like?".

Indeed, and that was a judgement call.  They are necessary IMO because
of other parts of standard Forth.  And they are standalone words which
don't have the (IMO) dramatic effect on the language that locals do.
(And I really needed them at the time for software transactional
memory, so I knew for certain that they had uses beyond their initial
motivation.)

> Sure, you can rewrite programs with multiple locals definitions in the
> VFX style, and they become longer and harder to read and understand.
> And of course shorter and easer to read and understand programs are
> just nice to have and not really necessary, like most other things,
> but I think that that multiple locals definition still lead to an
> overall improvement.

I do not disagree.  If you have words long enough really to need them,
yes, multiple locals definitions do undoubtedly lead to an
improvement.

>>"Back-and-forth noise" is just the normal use of English: you put a
>>stack item into a local only immediately to remove it.  That's what I
>>mean by "work", even if a very clever compiler can detect that you
>>didn't really mean to move the item and leaves it where it was.
> 
> So you mean something like static or dynamic executable code size from
> a simple Forth compiler?
> 
> Why not write that clearly?  Or if you mean something else, what do
> you mean?

I give up!

>>We really do disagree about that, and it seems to me that a word which
>>fetches two bytes from two pointers represents a pretty easily
>>identifiable concept
> 
> That's certainly not *one* concept, but even if it were, from your
> description I would expect such a word to have the stack effect
> ( addr1 addr2 -- c1 c2 ), whereas your @pair has ( a1 a2 - a1 a2 c1 c2).

Only if you dogmatically insist on the "a word must consume its
arguments" rule at the expense of the caller.

>>as does a word which bumps two pointers.
> 
> Not one concept, either.

Is so.  But this is what I'm talking about: pointless nitpicking of
minor details at the expense of the wider discussion.  So you don't
like my factoring.  I don't like yours.

>>> And do I really want to invent test cases for words that have no
>>> identifiable purpose?
>>
>>I'm trying to get my head around what this implies.  Are you really
>>saying that if you factor a word you have to test the factors, so that
>>is a pressure against factoring?
> 
> No.  You claimed: "it is often useful to separate out factors, for
> testing and clarity".  If I don't test them, it's not useful to factor
> them out for testing.

So don't then, then, but I would.  Not all programmers work in the
same way.

> And factoring out words that don't represent an identifiable concept
> reduces, rather than increases clarity.  So here we have have a case
> where none the reasons you gave for factoring apply (at least not
> for this factoring), and indeed there is a reason not to.

And there we must, again, agree to differ.  I have no problem
identifying what the words in question do and I don't think that
clarity is reduced.  But I'm not prepared to spend much effort
defending this factoring: I suspect it's not ideal, and a better job
could be done given some thought.

Andrew.

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Re: Why smudge? hughaguilar96@yahoo.com - 2014-09-30 19:25 -0700
  Re: Why smudge? november.nihal@gmail.com - 2014-10-01 08:54 -0700
    Re: Why smudge? albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-10-01 19:09 +0000
  Re: Why smudge? november.nihal@gmail.com - 2014-10-01 10:16 -0700
    Re: Why smudge? hughaguilar96@yahoo.com - 2014-10-01 18:54 -0700
  Re: Why smudge? hughaguilar96@yahoo.com - 2014-10-02 15:31 -0700
    Re: Why smudge? Michael Barry <barrym95838@yahoo.com> - 2014-10-02 16:35 -0700
      Re: Why smudge? hughaguilar96@yahoo.com - 2014-10-02 17:02 -0700
        Re: Why smudge? Michael Barry <barrym95838@yahoo.com> - 2014-10-02 17:51 -0700
          Re: Why smudge? hughaguilar96@yahoo.com - 2014-10-02 18:50 -0700
        Re: Why smudge? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-10-04 00:30 +0100
          Re: Why smudge? hughaguilar96@yahoo.com - 2014-10-03 17:40 -0700
            Re: Why smudge? Raimond Dragomir <raimond.dragomir@gmail.com> - 2014-10-03 23:00 -0700
              Pelc's effort to sabotage cross-compiler writing has a work-around now! hughaguilar96@yahoo.com - 2014-10-04 21:14 -0700
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-05 03:42 -0500
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! Enoch <emc.consultants@gmail.com> - 2014-10-05 10:43 -0700
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! hughaguilar96@yahoo.com - 2014-10-05 20:21 -0700
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-06 03:58 -0500
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! hughaguilar96@yahoo.com - 2014-10-05 17:09 -0700
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! Michael Barry <barrym95838@yahoo.com> - 2014-10-06 11:15 -0700
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! hughaguilar96@yahoo.com - 2014-10-06 18:52 -0700
                More ranting Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-07 03:48 -0500
                Re: More ranting albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-10-07 12:43 +0000
                Re: More ranting Bernd Paysan <bernd.paysan@gmx.de> - 2014-10-07 16:23 +0200
                Re: More ranting "Rod Pemberton" <buzzoff@nonamewhichexists.cmm> - 2014-10-16 01:03 -0400
                Re: More ranting Just Ian <superian@gmail.com> - 2014-10-16 07:14 -0700
                Re: More ranting Michael Barry <barrym95838@yahoo.com> - 2014-10-16 13:23 -0700
                uninitialized and implicitly initialized locals (was: More ranting) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-07 15:36 +0000
                Re: uninitialized and implicitly initialized locals (was: More ranting) Bernd Paysan <bernd.paysan@gmx.de> - 2014-10-07 22:15 +0200
                Re: uninitialized and implicitly initialized locals (was: More ranting) mhx@iae.nl - 2014-10-07 15:07 -0700
                Re: uninitialized and implicitly initialized locals (was: More ranting) Bernd Paysan <bernd.paysan@gmx.de> - 2014-10-08 03:11 +0200
                Re: uninitialized and implicitly initialized locals (was: More ranting) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-08 13:25 +0000
                Re: uninitialized and implicitly initialized locals (was: More ranting) hughaguilar96@yahoo.com - 2014-10-09 16:22 -0700
                Re: uninitialized and implicitly initialized locals (was: More ranting) "Rod Pemberton" <buzzoff@nonamewhichexists.cmm> - 2014-10-17 21:58 -0400
                Re: uninitialized and implicitly initialized locals (was: More ranting) mhx@iae.nl (Marcel Hendrix) - 2014-10-12 11:18 +0200
                Re: uninitialized and implicitly initialized locals (was: More ranting) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-08 12:35 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-07 15:27 -0500
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-08 12:56 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-08 08:24 -0500
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-08 15:32 +0000
                Simplified automatic scoping (was: uninitialized ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-08 16:06 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-08 11:57 -0500
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-08 12:18 -0500
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-09 14:19 +0000
                Re: uninitialized and implicitly initialized locals hughaguilar96@yahoo.com - 2014-10-09 14:42 -0700
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-09 14:07 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-09 10:44 -0500
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-10 16:03 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-10 13:35 -0500
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-11 10:53 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-12 11:34 -0500
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-15 12:44 +0000
                Re: uninitialized and implicitly initialized locals albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-10-15 14:34 +0000
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-15 15:03 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-15 11:10 -0500
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-16 12:19 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-17 03:56 -0500
                Re: uninitialized and implicitly initialized locals "Elizabeth D. Rather" <erather@forth.com> - 2014-10-17 07:48 -1000
                Re: uninitialized and implicitly initialized locals hughaguilar96@yahoo.com - 2014-10-17 19:26 -0700
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-18 12:55 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-18 13:21 -0500
                Re: uninitialized and implicitly initialized locals "Elizabeth D. Rather" <erather@forth.com> - 2014-10-18 08:44 -1000
                Re: uninitialized and implicitly initialized locals albert@spenarnc.xs4all.nl (Albert van der Horst) - 2014-10-19 09:53 +0000
                Re: uninitialized and implicitly initialized locals anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2014-10-20 12:48 +0000
                Re: uninitialized and implicitly initialized locals "Rod Pemberton" <buzzoff@nonamewhichexists.cmm> - 2014-10-20 16:24 -0400
                Re: uninitialized and implicitly initialized locals "Elizabeth D. Rather" <erather@forth.com> - 2014-10-20 10:30 -1000
                Re: uninitialized and implicitly initialized locals hughaguilar96@yahoo.com - 2014-10-20 16:23 -0700
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-26 04:16 -0500
                Re: uninitialized and implicitly initialized locals mhx@iae.nl (Marcel Hendrix) - 2014-10-26 11:32 +0200
                Re: uninitialized and implicitly initialized locals stephenXXX@mpeforth.com (Stephen Pelc) - 2014-10-26 14:27 +0000
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-26 13:56 -0500
                Re: uninitialized and implicitly initialized locals mhx@iae.nl (Marcel Hendrix) - 2014-10-26 20:32 +0200
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-26 16:18 -0500
                Re: uninitialized and implicitly initialized locals hughaguilar96@yahoo.com - 2014-10-26 15:05 -0700
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-26 17:53 -0500
                Re: uninitialized and implicitly initialized locals hughaguilar96@yahoo.com - 2014-10-26 16:30 -0700
                Re: uninitialized and implicitly initialized locals "Rod Pemberton" <buzzoff@nonamewhichexists.cmm> - 2014-10-27 01:45 -0400
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-27 12:21 -0500
                Re: uninitialized and implicitly initialized locals Andrew Haley <andrew29@littlepinkcloud.invalid> - 2014-10-26 17:57 -0500
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-10-06 20:55 +0100
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! hughaguilar96@yahoo.com - 2014-10-06 16:05 -0700
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-10-09 07:36 +0100
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! stephenXXX@mpeforth.com (Stephen Pelc) - 2014-10-10 01:52 +0000
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! hughaguilar96@yahoo.com - 2014-10-09 19:56 -0700
                Re: Pelc's effort to sabotage cross-compiler writing has a work-around now! "Rod Pemberton" <buzzoff@nonamewhichexists.cmm> - 2014-10-17 23:11 -0400
            Re: Why smudge? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-10-05 11:05 +0100
              Re: Why smudge? hughaguilar96@yahoo.com - 2014-10-05 19:48 -0700
                Re: Why smudge? Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2014-10-06 07:53 +0100
                Re: Why smudge? "Elizabeth D. Rather" <erather@forth.com> - 2014-10-05 21:29 -1000
              Re: Why smudge? hughaguilar96@yahoo.com - 2014-10-09 15:16 -0700
              Re: Why smudge? "Rod Pemberton" <buzzoff@nonamewhichexists.cmm> - 2014-10-16 01:03 -0400

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