Re: single-xt approach in the standard

From	Ruvim <ruvim.pinka@gmail.com>
Newsgroups	comp.lang.forth
Subject	Re: single-xt approach in the standard
Date	2024-09-17 17:04 +0400
Organization	A noiseless patient Spider
Message-ID	<vcbuog$3etuk$3@dont-email.me> (permalink)
References	<vcbn5e$3etuk$1@dont-email.me> <1a3ebf77c1ed8926d455a268e1309fe0@www.novabbs.com>

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On 2024-09-17 16:15, mhx wrote:
> On Tue, 17 Sep 2024 10:54:37 +0000, Ruvim wrote:
> 
>> Do you think that the Forth standard should recognize the classic
>> single-xt approach as possible for implementing a standard Forth system?
>>
>> The classic single-xt approach implies that only one execution token
>> (xt) is associated with a name token (nt), and only one name token is
>> associated with a word (a named Forth definition). And words whose
>> compilation semantics differ form default compilation semantics are
>> implemented as immediate words.
> 
> First define exactly the [new things] that can be done with an xt or an
> nt.

These things are well known.

For "xt" — "compile,", "execute", "catch".

For "nt" — "name>" (classic), "name>interpret", "name>compile", 
"name>string".

Also, "xt" and "nt" can be passed to the words that accept "x".

But it is irrelevant to my questions.

The single-xt approach was used in Forth systems long before Forth-94.
Should this approach be possible for a standard system?

There is a point of view (which I don't share) that it is impossible to 
implement the standard word `s"` (from the File word set) in a standard 
*program*. I.e., that the following definition for `s"` is not standard 
compliant:

   : s" ( "ccc" -- sd | )
     [char] " parse
     state @ if postpone sliteral exit then
     dup >r allocate throw tuck r@ move r>
   ; immediate

This effectively means that the classic single-xt approach is impossible 
for a standard system.

> What some of my customers tried is, by using standard words, associate
> generated code sequences with an xt (nearly impossible),

> or infer an nt from an xt (which is not 1-to-n [n>=3], and asymmetrical).

Even in some classic single-xt systems, one xt can be associated with 
many nt. (of course, what is now "nt" was known as "NFA").

> A limited/qualified guarantee for the nt-xt relationship can be useful.
> Example: DEFER aa  ' DROP IS aa  allows to recover the nt "DROP" from
> aa's DEFER@ and it is possible to disassemble linked lists of nt's.

You probably mean the *xt* "DROP" from aa's DEFER@

   DEFER aa
   ' DROP IS aa
   ' aa DEFER@ \ gives xt of DROP

Of cause, a standard program cannot disassemble linked lists of nt's

--
Ruvim

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single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-17 14:54 +0400
  Re: single-xt approach in the standard minforth@gmx.net (minforth) - 2024-09-17 11:20 +0000
    Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-17 15:59 +0400
      Re: single-xt approach in the standard Anthony Howe <achowe@snert.com> - 2024-09-17 14:58 -0400
        Re: single-xt approach in the standard dxf <dxforth@gmail.com> - 2024-09-18 13:39 +1000
          Standardization process (was: single-xt approach in the standard) Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 11:07 +0400
            Re: Standardization process dxf <dxforth@gmail.com> - 2024-09-18 20:16 +1000
              Re: Standardization process Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 14:51 +0400
                Re: Standardization process dxf <dxforth@gmail.com> - 2024-09-18 23:39 +1000
                Re: Standardization process Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 18:41 +0400
              Re: Standardization process Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 15:59 +0400
        Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 12:44 +0400
          Re: single-xt approach in the standard Gerry Jackson <do-not-use@swldwa.uk> - 2024-09-18 21:59 +0100
            Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-19 10:17 +0200
            Standard testsuite (was: single-xt approach in the standard) Ruvim <ruvim.pinka@gmail.com> - 2024-09-19 12:24 +0400
              Re: Standard testsuite (was: single-xt approach in the standard) albert@spenarnc.xs4all.nl - 2024-09-19 10:54 +0200
  Re: single-xt approach in the standard mhx@iae.nl (mhx) - 2024-09-17 12:15 +0000
    Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-17 17:04 +0400
      Re: single-xt approach in the standard minforth@gmx.net (minforth) - 2024-09-17 13:58 +0000
        Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-17 18:55 +0400
          Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-17 17:22 +0200
      Re: single-xt approach in the standard dxf <dxforth@gmail.com> - 2024-09-21 12:51 +1000
        Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-21 15:42 +0400
          Re: single-xt approach in the standard dxf <dxforth@gmail.com> - 2024-09-22 12:15 +1000
            Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-22 07:54 +0000
              Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-22 12:05 +0200
              Re: single-xt approach in the standard dxf <dxforth@gmail.com> - 2024-09-23 13:34 +1000
                Re: single-xt approach in the standard Anthony Howe <achowe@snert.com> - 2024-09-23 10:45 -0400
                Re: single-xt approach in the standard dxf <dxforth@gmail.com> - 2024-09-24 14:50 +1000
                Re: single-xt approach in the standard dxf <dxforth@gmail.com> - 2024-09-25 10:35 +1000
            Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-22 20:57 +0400
              Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-22 17:13 +0000
                Semantics as observable behavior (was: single-xt approach in the standard) Ruvim <ruvim.pinka@gmail.com> - 2024-09-22 23:53 +0400
                Re: Semantics as observable behavior (was: single-xt approach in the standard) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-22 21:04 +0000
                Re: Semantics as observable behavior Ruvim <ruvim.pinka@gmail.com> - 2024-09-23 02:01 +0400
                Re: Semantics as observable behavior Ruvim <ruvim.pinka@gmail.com> - 2024-09-23 11:36 +0400
              Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-22 21:34 +0200
                Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-23 00:02 +0400
                Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-23 09:40 +0200
                Re: single-xt approach in the standard minforth@gmx.net (minforth) - 2024-09-23 08:42 +0000
              Re: single-xt approach in the standard dxf <dxforth@gmail.com> - 2024-09-23 15:28 +1000
                Standard compliance for systems (was: single-xt approach in the standard) Ruvim <ruvim.pinka@gmail.com> - 2024-09-23 10:56 +0400
                Re: Standard compliance for systems dxf <dxforth@gmail.com> - 2024-11-22 16:49 +1100
                Re: Standard compliance for systems minforth@gmx.net (minforth) - 2024-11-22 10:11 +0000
                Re: Standard compliance for systems mhx@iae.nl (mhx) - 2024-11-22 11:35 +0000
                Re: Standard compliance for systems minforth@gmx.net (minforth) - 2024-11-22 13:11 +0000
                Re: Standard compliance for systems mhx@iae.nl (mhx) - 2024-11-22 15:26 +0000
                Re: Standard compliance for systems dxf <dxforth@gmail.com> - 2024-11-23 11:54 +1100
                Re: Standard compliance for systems albert@spenarnc.xs4all.nl - 2024-11-23 14:09 +0100
                Re: Standard compliance for systems dxf <dxforth@gmail.com> - 2024-11-24 12:02 +1100
      Re: single-xt approach in the standard Stephen Pelc <stephen@vfxforth.com> - 2024-09-21 14:47 +0000
        Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-21 23:18 +0400
          Re: single-xt approach in the standard Stephen Pelc <stephen@vfxforth.com> - 2024-09-22 12:09 +0000
            Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-22 14:28 +0000
            Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-22 21:20 +0200
      Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-22 11:53 +0200
        Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-23 01:15 +0400
          Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-23 10:36 +0200
            Re: single-xt approach in the standard mhx@iae.nl (mhx) - 2024-09-23 09:32 +0000
              Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-23 13:57 +0200
              Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-23 17:02 +0000
                Re: single-xt approach in the standard mhx@iae.nl (mhx) - 2024-09-23 19:20 +0000
            Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-23 14:16 +0400
              Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-23 16:52 +0000
                Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-25 11:27 +0400
    Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-17 17:18 +0200
  Re: single-xt approach in the standard Anthony Howe <achowe@snert.com> - 2024-09-17 15:12 -0400
    Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-17 19:25 +0000
      Re: single-xt approach in the standard Anthony Howe <achowe@snert.com> - 2024-09-24 07:08 -0400
    Re: single-xt approach in the standard Stephen Pelc <stephen@vfxforth.com> - 2024-09-17 23:04 +0000
      Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 10:10 +0400
        Re: single-xt approach in the standard mhx@iae.nl (mhx) - 2024-09-18 06:38 +0000
          Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-19 12:26 +0400
    Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 14:34 +0400
      Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 16:41 +0400
      Re: single-xt approach in the standard Hans Bezemer <the.beez.speaks@gmail.com> - 2024-09-18 18:43 +0200
        Re: single-xt approach in the standard albert@spenarnc.xs4all.nl - 2024-09-19 10:36 +0200
          Re: single-xt approach in the standard Hans Bezemer <the.beez.speaks@gmail.com> - 2024-09-20 14:58 +0200
  Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-17 21:15 +0000
  Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-18 12:15 +0400
  Re: single-xt approach in the standard peter.m.falth@gmail.com (PMF) - 2024-09-21 21:28 +0000
    Re: single-xt approach in the standard anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2024-09-22 07:23 +0000
    Re: single-xt approach in the standard Ruvim <ruvim.pinka@gmail.com> - 2024-09-22 21:34 +0400

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