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Re: Comparing addresses

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albert@spenarnc.xs4all.nl (Albert van der Horst) writes:
>In article <2013Oct22.131807@mips.complang.tuwien.ac.at>,
>Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:
>>And for programs, if there is a conscious decision
>>involved, programmers choose unsigned operations for addresses (the
>>bigger problem here is that if the programmer writes a signed
>>operation, this big will probably not be found through testing).
>
>I would much prefer to require programs that fail to work with negative
>addresses to declare an environmental dependancy.

Sure, such programs can define such an environmental dependency.  And
if they don't, they are just plain non-standard; so if they want to
comply at least partially with the standard, they are required to
declare such a dependency.

>It would be the
>normal case, much like requiring that C@ works on an octet.

While nearly all standard systems have c@ working on an octect (and
few programs depend on that), many systems give you addresses with the
MSB set:


 VFX Forth for Linux IA32
 © MicroProcessor Engineering Ltd, 1998-2012 

 Version: 4.60 [build 0501]
 Build date: 18 July 2012

 Free dictionary = 7900479 bytes [7715kb]


cr 2500000000 allocate throw dup . 2499999999 + dup . c@ . 
1648668680 -146298617 0  ok
bye [b8:~:3222] sf
SwiftForth i386-Linux 3.4.8a 21-Jul-2013 
cr 2500000000 allocate throw dup . 2499999999 + dup . c@ . 
1645961224 -149006073 0  ok

[b8:~:3223] ~/gforth-386/gforth
Gforth 0.7.9_20130821, Copyright (C) 1995-2012 Free Software Foundation, Inc.
Gforth comes with ABSOLUTELY NO WARRANTY; for details type `license'
Type `bye' to exit
cr 2500000000 allocate throw dup . 2499999999 + dup . c@ . 
1640062984 -154904313 0  ok

So writing programs with such an environmental dependency is not wise.
So we do need a way to flag such environmental dependencies in
programs.

>P.S.
>qsort is a kind of a problem. It is a would be general purpose
>tool and at the same time a carnal thing.

What is carnal about it?

- anton
-- 
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
     New standard: http://www.forth200x.org/forth200x.html
   EuroForth 2013: http://www.euroforth.org/ef13/

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Baden's recursive Quicksort revisited "Ed" <invalid@invalid.com> - 2013-10-11 01:31 +1000
  Re: Baden's recursive Quicksort revisited albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-10 15:49 +0000
  Re: Baden's recursive Quicksort revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-10 17:42 +0000
    Re: Baden's recursive Quicksort revisited "Ed" <invalid@invalid.com> - 2013-10-18 15:16 +1000
    Re: Baden's recursive Quicksort revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-20 03:18 -0500
      Re: Baden's recursive Quicksort revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-21 16:33 +0000
  Re: Baden's recursive Quicksort revisited Hans Bezemer <the.beez.speaks@gmail.com> - 2013-10-11 12:03 +0200
    Re: Baden's recursive Quicksort revisited Alex McDonald <blog@rivadpm.com> - 2013-10-11 05:15 -0700
      Re: Baden's recursive Quicksort revisited "Ed" <invalid@invalid.com> - 2013-10-13 12:25 +1000
        Re: Baden's recursive Quicksort revisited "Alex McDonald" <blog@rivadpm.com> - 2013-10-13 08:59 +0100
          Re: Baden's recursive Quicksort revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-13 04:50 -0500
            Comparing addresses (was: Baden's recursive Quicksort revisited) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-15 15:17 +0000
              Re: Comparing addresses Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-15 14:34 -0500
                Re: Comparing addresses anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-16 14:15 +0000
                Re: Comparing addresses Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-20 02:51 -0500
                Re: Comparing addresses anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-22 11:18 +0000
                Re: Comparing addresses albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-22 13:26 +0000
                Re: Comparing addresses anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-22 13:39 +0000
                Re: Comparing addresses Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-22 13:30 -0500
                Re: Comparing addresses anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-23 07:48 +0000
                Re: Comparing addresses m.a.m.hendrix@tue.nl - 2013-10-23 23:49 -0700
                Re: Comparing addresses anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-24 09:01 +0000
        Re: Baden's recursive Quicksort revisited albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-13 12:06 +0000
          Re: Baden's recursive Quicksort revisited all2001@spambog.com (Wolfgang Allinger) - 2013-10-13 11:42 -0400
    Re: Baden's recursive Quicksort revisited "Ed" <invalid@invalid.com> - 2013-10-13 12:27 +1000
      Re: Baden's recursive Quicksort revisited Hans Bezemer <the.beez.speaks@gmail.com> - 2013-10-16 10:35 +0200
        Re: Baden's recursive Quicksort revisited Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-16 03:51 -0500
        Re: Baden's recursive Quicksort revisited albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-16 10:50 +0000
          Re: Baden's recursive Quicksort revisited anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-16 14:27 +0000
        Re: Baden's recursive Quicksort revisited "Ed" <invalid@invalid.com> - 2013-10-18 15:37 +1000

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