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Groups > comp.lang.forth > #41075

Re: RfD: Quotations

From Gerry Jackson <gerry@jackson9000.fsnet.co.uk>
Newsgroups comp.lang.forth
Subject Re: RfD: Quotations
Date 2015-08-03 16:40 +0100
Organization A noiseless patient Spider
Message-ID <mpo1tm$i6m$1@dont-email.me> (permalink)
References <mp8o6q$plc$1@dont-email.me> <mpgmfr$2dq$1@dont-email.me> <2015Aug1.161848@mips.complang.tuwien.ac.at> <mpj90s$5hp$1@dont-email.me> <2015Aug2.073624@mips.complang.tuwien.ac.at>

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On 02/08/2015 06:36, Anton Ertl wrote:
> Bernd Paysan <bernd.paysan@gmx.de> writes:
>> Anton Ertl wrote:
>>
>>>> Use of RECURSE after DOES> is an ambiguous condition (which really ought
>>>> to be resolved)
>>>
>>> Yes.  My vote would be for making it call the place right after the
>>> DOES>.  Should not be hard to implement on any Forth system.

I agree. Given that factoring out the DOES> part of a CREATE ... DOES> 
definition should result in identical behaviour, recursing to the code 
after DOES> is surely the correct thing to do.

>>
>> Current Gforth does so (after we changed DOES> internals considerably to get
>> rid of the special-casing in how DOES> stuff is called).  Test example:
>>
>> : test create , does> @ dup if '.' emit recurse then ;
>> here 0 ,
>> here swap ,
>> here swap ,
>> here swap ,
>> test foo
>> foo .... ok
>> . 0 ok
>

My system gives that result.

> And that's pretty much the only use case of this kind of recursion:
> When the CREATEd word is the head of a recursive data structure, and
> you want to walk it right in the DOES> part (instead of factoring the
> walk out).  Probably not really useful, but calling the named word is
> also only useful for parlor tricks.
>

A quick survey of a few systems indicates that for the above definition 
(with [CHAR] . replacing '.'

VFX Forth issues an error message ERR: Invalid use of RECURSE.

SwiftForth, Win32 Forth and iForth recurse to TEST

If we factor out the DOES> part e.g.

: bar does> @ dup if [char] . emit recurse then ;
: test create , bar ;
here 0 ,
here swap ,
here swap ,
here swap ,
test foo
foo

VFX Forth reports the same error when compiling BAR
SwiftForth, Win32 Forth and iForth recurse to BAR (not the code after 
DOES>) emitting 1 '.'
With Win32Forth re-executing FOO displays an increasing number of '.'s 
after the ok prompt.

There's probably little chance of that ambiguous condition being removed

-- 
Gerry

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Thread

RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-28 21:22 +0100
  Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-29 07:35 +0000
    Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 14:20 +0100
  Re: RfD: Quotations Ron Aaron <rambamist@gmail.com> - 2015-07-29 13:44 +0300
    Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 13:42 +0100
  Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-29 05:35 -0700
    Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-29 13:34 +0000
      Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-29 07:35 -0700
        Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-29 15:05 +0000
        Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 16:19 +0100
          Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-07-29 21:48 +0100
      Re: RfD: Quotations mhx@iae.nl - 2015-07-29 11:13 -0700
        Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-30 13:04 +0000
    Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 15:07 +0100
      Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-29 07:44 -0700
        Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-29 15:12 +0000
        Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 16:18 +0100
          Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-29 18:37 +0200
            Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 17:55 +0100
              Re: RfD: Quotations "Elizabeth D. Rather" <erather@forth.com> - 2015-07-29 19:51 -0500
                Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 03:31 +0200
                Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-29 19:30 -0700
                Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-29 21:19 -0700
                Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-29 21:37 -0700
                Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-30 11:45 +0000
                Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-30 08:07 -0700
                Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-31 10:54 +0000
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 12:48 +0100
                Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-31 05:40 -0700
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 14:46 +0100
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 14:50 +0100
                Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-31 14:46 +0000
                Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-31 13:16 -0700
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 21:49 +0100
                Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-29 22:42 -0700
                Re: RfD: Quotations "Elizabeth D. Rather" <erather@forth.com> - 2015-07-30 08:46 -0500
                Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-29 21:40 -0700
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 10:01 +0100
                Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 12:00 +0200
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 11:10 +0100
                Re: RfD: Quotations Coos Haak <chforth@hccnet.nl> - 2015-07-30 16:35 +0200
            Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-29 16:53 +0000
          Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-29 19:03 +0200
            Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 18:24 +0100
              Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 01:38 +0200
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 09:10 +0100
                Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 12:06 +0200
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 11:21 +0100
                Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 14:00 +0200
                Re: RfD: Quotations franck.bensusan@gmail.com - 2015-07-30 06:59 -0700
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 10:53 +0100
            Re: RfD: Quotations Paul Rubin <no.email@nospam.invalid> - 2015-07-29 10:35 -0700
              Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 01:45 +0200
                Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 03:17 +0200
                Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-29 19:21 -0700
                Re: RfD: Quotations Paul Rubin <no.email@nospam.invalid> - 2015-07-29 23:04 -0700
                Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 12:38 +0200
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 12:09 +0100
                Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 13:26 +0200
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 09:47 +0100
                Re: RfD: Quotations Raimond Dragomir <raimond.dragomir@gmail.com> - 2015-07-31 02:51 -0700
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 11:21 +0100
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 09:11 +0100
            Re: RfD: Quotations Paul Rubin <no.email@nospam.invalid> - 2015-07-29 11:36 -0700
              Re: RfD: Quotations Paul Rubin <no.email@nospam.invalid> - 2015-07-29 11:37 -0700
            Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-30 13:07 +0000
              Re: RfD: Quotations Bernd Linsel <bl1@gmx.com> - 2015-07-30 16:25 +0200
          Re: RfD: Quotations mhx@iae.nl - 2015-07-29 11:16 -0700
            Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 20:27 +0100
              Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-07-29 21:57 +0100
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-29 22:48 +0100
                Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-07-31 12:34 +0100
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 13:00 +0100
                Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-31 14:31 +0000
                Re: RfD: Quotations mhx@iae.nl - 2015-07-31 11:32 -0700
              Re: RfD: Quotations mhx@iae.nl - 2015-07-29 21:42 -0700
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 09:57 +0100
          Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-29 17:21 -0700
            Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 09:56 +0100
              Re: RfD: Quotations franck.bensusan@gmail.com - 2015-07-30 04:15 -0700
                Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 12:30 +0100
                Re: RfD: Quotations franck.bensusan@gmail.com - 2015-07-30 05:04 -0700
                Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-30 13:07 -0700
  Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-29 16:52 -0700
    Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 09:53 +0100
  Re: RfD: Quotations Bernd Paysan <bernd.paysan@gmx.de> - 2015-07-30 21:45 +0200
    Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-30 13:25 -0700
      Re: RfD: Quotations Julian Fondren <ayrnieu@gmail.com> - 2015-07-30 15:11 -0700
        Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 09:11 +0100
          Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-07-31 12:04 +0100
    Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-30 22:51 +0100
      Re: RfD: Quotations hughaguilar96@gmail.com - 2015-07-30 22:38 -0700
        Re: RfD: Quotations "Rod Pemberton" <boo@fasdfrewar.cdm> - 2015-07-31 02:10 -0400
        Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 09:01 +0100
          Re: RfD: Quotations hughaguilar96@gmail.com - 2015-08-01 14:59 -0700
            Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-08-01 23:36 +0100
              Re: RfD: Quotations Bernd Paysan <bernd.paysan@gmx.de> - 2015-08-02 01:19 +0200
                Re: RfD: Quotations hughaguilar96@gmail.com - 2015-08-01 18:27 -0700
                Re: RfD: Quotations hughaguilar96@gmail.com - 2015-08-09 14:34 -0700
  Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-07-31 08:52 +0000
    Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 11:57 +0100
  Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-07-31 21:42 +0100
    Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-07-31 22:25 +0100
      Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-07-31 23:39 +0100
        Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-08-01 10:59 +0100
    Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-08-01 14:18 +0000
      Re: RfD: Quotations Bernd Paysan <bernd.paysan@gmx.de> - 2015-08-01 22:10 +0200
        Re: RfD: Quotations anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2015-08-02 05:36 +0000
          Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-08-03 16:40 +0100
            Re: RfD: Quotations "Alex McDonald" <blog@rivadpm.com> - 2015-08-03 18:02 +0100
              Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-08-03 20:22 +0100
            Re: RfD: Quotations Coos Haak <chforth@hccnet.nl> - 2015-08-04 02:10 +0200
              Re: RfD: Quotations Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2015-08-04 08:49 +0100
  Re: RfD: Quotations hughaguilar96@gmail.com - 2015-08-01 15:15 -0700

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