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Re: FORTH Trouble--Please Show Me

From mhx@iae.nl (Marcel Hendrix)
Subject Re: FORTH Trouble--Please Show Me
Newsgroups comp.lang.forth
Message-ID <82631413938435@frunobulax.edu> (permalink)
Date 2012-10-22 21:40 +0200
References <7xk3ujx8br.fsf@ruckus.brouhaha.com>
Organization Wanadoo

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Paul Rubin <no.email@nospam.invalid> writes Re: FORTH Trouble--Please Show Me

> mhx@iae.nl writes:
>> -- second version
>> : derivative ( xt1 -- xt2 ) ( F: h -- ) \ "name" 
>> 	CREATE	F, , DOES> F@+ @ derive ;
>>
>> ' FSQR 1e-4 derivative d
>> CR 3e FSQR  F.	.(  \ prints 9 )
>> CR 3e d F. 	.(  \ prints approximately 6 )
>> CR 4e d F. 	.(  \ prints approximately 8 )

> This is better, though it allocates permanent space in the dictionary
> rather than returning a temporary value (the Python program used a
> variable but the Forth equivalent would be to return a value on the
> stack).  Of course Python uses something like ALLOCATE under the hood,
> and automatically reclaims the space once the value has no live
> references left, and you could do something similar with Anton's garbage
> collector for Gforth.  Anyway I'll accept that your second version is
> reasonably close, and only somewhat messy.

In a Forth context (this is CLF) it is absolutely no limitation that 
dictionary space is allotted. This is because "derivative" is executed 
only once [here *]. The data space allotted by F, and , is insignificant 
with respect to d's header space.

As Forth is an interpreter (as is Python!), the space taken by words 
like d can never be reclaimed: at any time the user may type "d". Only 
the interpreter's exit (i.e. BYE) can trigger the return of ALLOTted 
space.

If use of 'd-type' words is such that they can't be reached by the interpreter
anymore, this can only mean that MARKER has been executed. In that case all 
space is (automatically) reclaimed. Forth words can execute MARKER words.

I admit that I am resisting going along with your silent demand to show a 
extremely messy and complicated bastard closure in Forth :-)
A basic idea in Forth is to not building in hooks that may never be used [*]. 

Believe me, the better your specification for a useful piece of code that 
absolutely needs closures, the happier both of us will be.

And yes, I really think that the Forth interpreter should be kept in all
Forth programs, and that all Forth programs should be built from source.

-marcel

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FORTH Trouble--Please Show Me "Charles Richmond" <numerist@aquaporin4.com> - 2012-10-17 16:56 -0500
  Re: FORTH Trouble--Please Show Me all2001@spambog.com (Wolfgang Allinger) - 2012-10-17 19:11 -0300
    Re: FORTH Trouble--Please Show Me Mark Wills <forthfreak@gmail.com> - 2012-10-18 01:15 -0700
      Re: FORTH Trouble--Please Show Me "Charles Richmond" <numerist@aquaporin4.com> - 2012-10-18 05:25 -0500
  Re: FORTH Trouble--Please Show Me mhx@iae.nl (Marcel Hendrix) - 2012-10-18 00:14 +0200
    Re: FORTH Trouble--Please Show Me Spam@ControlQ.com - 2012-10-17 18:45 -0400
      Re: FORTH Trouble--Please Show Me Anonymous <nobody@remailer.paranoici.org> - 2012-10-18 08:49 +0000
        Re: FORTH Trouble--Please Show Me Spam@ControlQ.com - 2012-10-18 15:58 -0400
          Re: FORTH Trouble--Please Show Me albert@spenarnc.xs4all.nl (Albert van der Horst) - 2012-10-18 21:53 +0000
          Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-19 18:39 -0700
            Re: FORTH Trouble--Please Show Me Mark Wills <markrobertwills@yahoo.co.uk> - 2012-10-19 23:22 -0700
            Re: FORTH Trouble--Please Show Me "Charles Richmond" <numerist@aquaporin4.com> - 2012-10-21 13:40 -0500
          Re: FORTH Trouble--Please Show Me "Elizabeth D. Rather" <erather@forth.com> - 2012-10-19 21:00 -1000
            Re: FORTH Trouble--Please Show Me "A. K." <akk@nospam.org> - 2012-10-20 09:18 +0200
              Re: FORTH Trouble--Please Show Me "Elizabeth D. Rather" <erather@forth.com> - 2012-10-20 08:40 -1000
          Re: FORTH Trouble--Please Show Me mhx@iae.nl (Marcel Hendrix) - 2012-10-21 12:22 +0200
            Re: FORTH Trouble--Please Show Me Doug Hoffman <glidedog@gmail.com> - 2012-10-21 08:46 -0400
      Re: FORTH Trouble--Please Show Me mhx@iae.nl (Marcel Hendrix) - 2012-10-18 21:08 +0200
        Re: FORTH Trouble--Please Show Me Mark Wills <markrobertwills@yahoo.co.uk> - 2012-10-18 12:29 -0700
  Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-17 20:24 -0700
    Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-19 19:46 -0400
      Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-19 18:46 -0700
        Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-20 21:03 -0400
          Re: FORTH Trouble--Please Show Me "Elizabeth D. Rather" <erather@forth.com> - 2012-10-20 15:40 -1000
          Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-20 18:52 -0700
            Re: FORTH Trouble--Please Show Me "Elizabeth D. Rather" <erather@forth.com> - 2012-10-20 16:27 -1000
          Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-20 20:56 -0700
            Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-21 09:40 -0400
              Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-21 12:51 -0700
                Re: FORTH Trouble--Please Show Me mhx@iae.nl (Marcel Hendrix) - 2012-10-21 23:50 +0200
                Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-21 17:11 -0700
                Re: FORTH Trouble--Please Show Me mhx@iae.nl - 2012-10-22 00:19 -0700
                Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-22 00:41 -0700
                Re: FORTH Trouble--Please Show Me Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-22 09:31 -0500
                Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-22 08:13 -0700
                Re: FORTH Trouble--Please Show Me mhx@iae.nl (Marcel Hendrix) - 2012-10-22 21:40 +0200
                Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-22 13:14 -0700
                Re: FORTH Trouble--Please Show Me "Elizabeth D. Rather" <erather@forth.com> - 2012-10-22 10:41 -1000
                Re: FORTH Trouble--Please Show Me mhx@iae.nl (Marcel Hendrix) - 2012-10-22 23:21 +0200
                Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-22 14:27 -0700
                Re: FORTH Trouble--Please Show Me "Elizabeth D. Rather" <erather@forth.com> - 2012-10-22 14:16 -1000
                Re: FORTH Trouble--Please Show Me Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-10-23 21:42 +0100
                Re: FORTH Trouble--Please Show Me vandys@vsta.org - 2012-10-22 00:24 +0000
                Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-22 04:12 -0400
                Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-22 01:40 -0700
                Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-22 02:39 -0700
                Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-22 02:30 -0700
                Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-22 22:27 -0400
                Re: FORTH Trouble--Please Show Me David Thompson <dave.thompson2@verizon.net> - 2012-11-04 22:18 -0500
                Re: FORTH Trouble--Please Show Me Bernd Paysan <bernd.paysan@gmx.de> - 2012-11-05 15:35 +0100
                Re: FORTH Trouble--Please Show Me humptydumpty <ouatubi@gmail.com> - 2012-10-22 12:22 -0700
                Re: FORTH Trouble--Please Show Me Paul Rubin <no.email@nospam.invalid> - 2012-10-22 12:51 -0700
                Re: FORTH Trouble--Please Show Me humptydumpty <ouatubi@gmail.com> - 2012-10-22 23:40 -0700
                Re: FORTH Trouble--Please Show Me anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-23 12:50 +0000
                Re: FORTH Trouble--Please Show Me humptydumpty <ouatubi@gmail.com> - 2012-10-24 09:13 -0700
                Re: FORTH Trouble--Please Show Me anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-25 12:31 +0000
                Re: FORTH Trouble--Please Show Me humptydumpty <ouatubi@gmail.com> - 2012-10-26 09:58 -0700
              Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-21 16:24 -0700
                Re: FORTH Trouble--Please Show Me Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-22 02:51 +0200
                Re: FORTH Trouble--Please Show Me Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-21 19:55 -0500
                Re: FORTH Trouble--Please Show Me Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-22 03:02 +0200
                Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-22 03:50 -0400
                Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-22 01:03 -0700
                Re: FORTH Trouble--Please Show Me stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-22 10:12 +0000
                Re: FORTH Trouble--Please Show Me stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-22 10:08 +0000
                Re: FORTH Trouble--Please Show Me Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-22 18:06 +0200
                Re: FORTH Trouble--Please Show Me mhx@iae.nl (Marcel Hendrix) - 2012-10-22 22:14 +0200
                Re: FORTH Trouble--Please Show Me albert@spenarnc.xs4all.nl (Albert van der Horst) - 2012-10-23 00:50 +0000
                Re: FORTH Trouble--Please Show Me Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-23 03:43 +0200
                Re: FORTH Trouble--Please Show Me Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-23 03:14 -0500
                Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-22 19:54 -0700
                Re: FORTH Trouble--Please Show Me Mark Wills <markrobertwills@yahoo.co.uk> - 2012-10-22 22:59 -0700
                Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-24 09:23 -0700
                Re: FORTH Trouble--Please Show Me stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-23 10:33 +0000
                Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-24 10:05 -0700
                Re: FORTH Trouble--Please Show Me Doug Hoffman <glidedog@gmail.com> - 2012-10-24 14:56 -0400
                Re: FORTH Trouble--Please Show Me anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-23 11:50 +0000
                Re: FORTH Trouble--Please Show Me stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-23 14:39 +0000
                Application Benchmarks (was: FORTH Trouble--Please Show Me) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-23 15:59 +0000
                Re: Application Benchmarks (was: FORTH Trouble--Please Show Me) stephenXXX@mpeforth.com (Stephen Pelc) - 2012-10-24 14:33 +0000
                Re: Application Benchmarks (was: FORTH Trouble--Please Show Me) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-25 14:19 +0000
                Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-22 03:56 -0400
                Re: FORTH Trouble--Please Show Me "Elizabeth D. Rather" <erather@forth.com> - 2012-10-21 22:12 -1000
                Re: FORTH Trouble--Please Show Me Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-22 02:51 -0700
          Re: FORTH Trouble--Please Show Me Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-21 05:29 -0500
            Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-21 09:35 -0400
            Re: FORTH Trouble--Please Show Me Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-21 15:44 +0200
              Re: FORTH Trouble--Please Show Me Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-21 18:43 -0500
              Re: FORTH Trouble--Please Show Me "Rod Pemberton" <do_not_have@notemailnotz.cnm> - 2012-10-22 04:20 -0400

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