Re: ?EXEC

From	Bernd Paysan <bernd.paysan@gmx.de>
Newsgroups	comp.lang.forth
Subject	Re: ?EXEC
Date	2012-06-21 22:15 +0200
Organization	1&1 Internet AG
Message-ID	<jrvvcd$853$1@online.de> (permalink)
References	(3 earlier) <2012Jun17.142751@mips.complang.tuwien.ac.at> <m5s4bd.5r0@spenarnc.xs4all.nl> <2012Jun18.153125@mips.complang.tuwien.ac.at> <jrog44$jsi$1@online.de> <2012Jun19.165240@mips.complang.tuwien.ac.at>

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Anton Ertl wrote:
> And in what way is this a misunderstanding?  What do you suggest to
> replace "reading the standard" with?  Divine inspiration?

Asking the people who wrote it.  We don't need divine inspiration.

And: The way we standardize things is by looking at common practice.  If 
we find a feature in the standard which is *not* common practice, it's 
time to de-standardize it.

> Anyway, even if we agree that we don't want to put the onus of
> implementing S" and TO properly on all systems (i.e., such that they
> pass postponetest.fs), it's a good idea for implementors to pass as
> much of postponetest.fs as possible, because there is production code
> out there that will fail on systems where certain postponetest.fs
> tests fail.

Maybe.  There are however quite a lot of Forths out there which fail 
postponetest.fs, and they have production code running on it.  I had 
quite some troubles with VFX Forth with Postpone, and I was "the only 
one" who used strange things where Stephen's source inliner failed.  The 
tests required to break that weren't even part of test/postpone.fs, it 
would be something like

: n+: ( n -- )  >r  : r> postpone literal postpone + postpone ; ;
3 n+: 3+
: bar 3+ ;
{ 5 bar -> 8 }

With the source inliner, VFX Forth did not see any source after the 
definition of 3+, so it inlined that "nothing" into bar.  I should 
really add this one to postponetest.fs

> And putting ?COMP in an IF and DO that pass postponetest.fs will make
> them fail postponetest.fs.

Yes.  But the question is whether postponetest really tests something 
that is worth testing.  It tests whether postpone is able to preserve 
the compilation semantics of its postponed words in interpretation 
state.

> What do you mean by that?  ?COMP is a check of STATE at run-time.  It
> has this problem by nature.  If you mean that on some systems I have
> ways to do properly what people try (and fail) to achieve with ?COMP,
> that's true, but that's not ?COMP.  It's, e.g., Gforth's COMPILE-ONLY.

Yes, but COMPILE-ONLY (which sets a header flag) is not a standard word.  
It's a nice way to implement this feature, but it has to be pretty deep 
in the system. You can't add it later.  It's something that (including 
other features) makes Gforth EC 16kB large, while 4kB probably should be 
enough on an embedded system (and that 4k will not check anything and 
only implement core words).

>>But the standard does not
>>mandate these extensions, they are quality-of-implementation issues
>>(and not having too many features is considered as quality of
>>implementation by some people in the Forth community).
> 
> In particular, one should not include misfeatures like ?COMP.  And
> that's not just a quality-of-implementation issue.

IMHO, if the ANS Forth TC wanted to deliberately outlaw this misfeature 
(which was pretty common back then), it should have said so explicitely, 
and offer a way how to do it properly.

-- 
Bernd Paysan
"If you want it done right, you have to do it yourself"
http://bernd-paysan.de/

Thread

?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-15 20:40 +0000
  Re: ?EXEC "Ed" <invalid@nospam.com> - 2012-06-16 11:14 +1000
  Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-16 07:10 -0700
    Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-17 03:01 +0000
      Re: ?EXEC "Ed" <invalid@nospam.com> - 2012-06-17 13:36 +1000
      Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-17 12:27 +0000
        Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-17 20:45 +0000
          Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-18 13:31 +0000
            Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-18 18:29 +0000
              Re: ?EXEC "Elizabeth D. Rather" <erather@forth.com> - 2012-06-18 08:01 -1000
              Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-19 14:09 +0000
                Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-19 10:51 -0500
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-19 16:04 +0000
                Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-19 12:45 -0500
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-20 10:50 +0000
                Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-20 07:10 -0500
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-20 12:47 +0000
                Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-19 22:52 +0000
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-20 10:59 +0000
                Defining Compilation Behaviour - was Re: ?EXEC JennyB <jennybrien@googlemail.com> - 2012-06-21 04:58 -0700
                Re: Defining Compilation Behaviour - was Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-21 15:44 +0000
            Re: ?EXEC Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-19 02:11 +0200
              Re: ?EXEC "Elizabeth D. Rather" <erather@forth.com> - 2012-06-18 14:45 -1000
                Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-19 10:48 +0000
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-19 15:53 +0000
                Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-19 23:00 +0000
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-20 11:09 +0000
                Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-20 07:39 -0700
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-20 15:32 +0000
                Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-21 11:24 -0700
                Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-20 22:43 +0000
                Re: ?EXEC Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-21 21:39 +0200
                Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-22 02:33 -0500
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-22 11:12 +0000
                Re: ?EXEC Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-22 21:34 +0200
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-24 14:58 +0000
                Re: ?EXEC Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-24 23:53 +0200
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-19 15:43 +0000
              Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-19 14:52 +0000
                Re: ?EXEC Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-21 22:15 +0200
                Re: ?EXEC stephenXXX@mpeforth.com (Stephen Pelc) - 2012-06-22 10:32 +0000
                Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-22 05:49 -0500
                Alternatives to S" and TO (was: ?EXEC) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-22 15:19 +0000
                Re: Alternatives to S'' and TO mhx@iae.nl (Marcel Hendrix) - 2012-06-22 20:37 +0200
                Re: Alternatives to S'' and TO anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-23 14:46 +0000
                Re: Alternatives to S" and TO (was: ?EXEC) BruceMcF <agila61@netscape.net> - 2012-06-22 12:32 -0700
                Re: Alternatives to S" and TO Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-23 03:07 -0500
                Re: Alternatives to S" and TO anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-23 13:32 +0000
                Re: Alternatives to S" and TO Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-24 08:50 -0500
                Re: Alternatives to S" and TO anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-24 15:39 +0000
                Re: Alternatives to S" and TO Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-25 04:49 -0500
                Re: Alternatives to S" and TO BruceMcF <agila61@netscape.net> - 2012-06-25 07:17 -0700
                Re: Alternatives to S" and TO Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-25 10:13 -0500
                Re: Alternatives to S" and TO (was: ?EXEC) Alex McDonald <blog@rivadpm.com> - 2012-06-23 16:01 -0700
                Re: Alternatives to S" and TO (was: ?EXEC) Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-24 01:59 +0200
                Re: Alternatives to S" and TO (was: ?EXEC) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-24 13:21 +0000
                Re: Alternatives to S" and TO (was: ?EXEC) Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-24 16:50 +0000
                Re: Alternatives to S" and TO (was: ?EXEC) Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-27 23:30 +0200
                Re: Alternatives to S" and TO (was: ?EXEC) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-24 13:15 +0000
                Re: Alternatives to S" and TO (was: ?EXEC) Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-24 16:47 +0000
                Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-22 20:34 +0000
                Re: ?EXEC Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-22 21:46 +0200
                Re: ?EXEC "Elizabeth D. Rather" <erather@forth.com> - 2012-06-22 10:16 -1000
                Re: ?EXEC Bernd Paysan <bernd.paysan@gmx.de> - 2012-06-22 22:43 +0200
                Re: ?EXEC "Elizabeth D. Rather" <erather@forth.com> - 2012-06-22 11:18 -1000
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-23 13:50 +0000
      Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-17 10:41 -0700
  Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-17 12:52 +0000
    Re: ?EXEC "Elizabeth D. Rather" <erather@forth.com> - 2012-06-17 08:03 -1000
      Re: ?EXEC "Ed" <invalid@nospam.com> - 2012-06-18 15:06 +1000
        Re: ?EXEC "Elizabeth D. Rather" <erather@forth.com> - 2012-06-17 20:31 -1000
          Re: ?EXEC "Ed" <invalid@nospam.com> - 2012-06-21 13:07 +1000
            Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-21 14:00 +0000
              Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-21 07:51 -0700
              Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-21 15:39 +0000
                Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-21 20:28 +0000
                Re: ?EXEC "Ed" <invalid@nospam.com> - 2012-06-28 14:22 +1000
                Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-28 04:00 -0500
            Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-21 16:09 +0000
            Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-21 11:51 -0500
              Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-21 11:21 -0700
                Re: ?EXEC Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-06-22 01:42 -0500
                Re: ?EXEC "Elizabeth D. Rather" <erather@forth.com> - 2012-06-21 21:47 -1000
                Re: ?EXEC anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-06-22 15:10 +0000
                Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-22 20:39 +0000
                Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-22 12:47 -0700
                Re: ?EXEC BruceMcF <agila61@netscape.net> - 2012-06-22 12:53 -0700
        Re: ?EXEC stephenXXX@mpeforth.com (Stephen Pelc) - 2012-06-21 08:39 +0000
          Re: ?EXEC "Ed" <invalid@nospam.com> - 2012-06-23 15:36 +1000
            Re: ?EXEC stephenXXX@mpeforth.com (Stephen Pelc) - 2012-06-23 10:58 +0000
              Re: ?EXEC "Ed" <invalid@nospam.com> - 2012-06-25 14:26 +1000
                Re: ?EXEC stephenXXX@mpeforth.com (Stephen Pelc) - 2012-06-25 08:37 +0000
      Re: ?EXEC Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-06-18 10:34 +0000
  Re: ?EXEC Coos Haak <chforth@hccnet.nl> - 2012-06-18 17:47 +0200
    Re: ?EXEC Coos Haak <chforth@hccnet.nl> - 2012-06-18 17:49 +0200
  Re: ?EXEC jacko <jackokring@gmail.com> - 2012-06-22 15:43 -0700

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