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Re: Simple Strings

From anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups comp.lang.forth
Subject Re: Simple Strings
Date 2013-10-15 14:57 +0000
Organization Institut fuer Computersprachen, Technische Universitaet Wien
Message-ID <2013Oct15.165713@mips.complang.tuwien.ac.at> (permalink)
References (3 earlier) <bKSdnYtBqcOAusTPnZ2dnUVZ8qudnZ2d@supernews.com> <61ac7a21-f158-4126-b739-90189516561c@googlegroups.com> <epWdnXID88CZyMTPnZ2dnUVZ8nOdnZ2d@supernews.com> <v-idnTD_U4tUXMTPnZ2dnUVZ_vGdnZ2d@supernews.com> <2qidnf3ksPZM1cfPnZ2dnUVZ8oidnZ2d@supernews.com>

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Andrew Haley <andrew29@littlepinkcloud.invalid> writes:
>What is a "real advantage" when it comes to notation?
>
>I'll knock the question right back: what is the real advantage of
>a word like DOES>
>
>assembler definitions
>: instruction ( n)   create ,  does> @ , ;
>
>over a word called USE that takes an XT and sets the latest
>definition's action:
>
>: (instruction) ( - n)   @ , ;
>: instruction ( n)   create ,  ['] (instruction) use ;
>
>?
>
>There's no "real advantage" to DOES>, is there?  Why not have words
>for the two actions like this?

Actually, that's a cleaner approach that avoids issues like specifying
the meanining of RECURSE in the DOES> part and locals across DOES>, or
control flow around DOES>.

And once we have quotations, it's just as convenient to write:

: instruction ( n "name" -- )
  create ,
  [: @ , ;] use ;

For a more interesting example, consider (from
http://www.complang.tuwien.ac.at/forth/struct.fs):

: dofield ( -- )
does> ( name execution: addr1 -- addr2 )
    @ + ;

: dozerofield ( -- )
    immediate
does> ( name execution: -- )
    drop ;

: field ( align1 offset1 align size "name" --  align2 offset2 )
    \ name execution: addr1 -- addr2
    2 pick >r \ this uglyness is just for optimizing with dozerofield
    create-field
    r> if \ offset<>0
	dofield
    else
	dozerofield
    then ;

This could be written as:

: field ( align1 offset1 align size "name" --  align2 offset2 )
    2 pick >r create-field r> if
      [: @ + ;]
    else
      immediate [: drop ;]
    then
    use ;

(USE is in use for a different purpose, but I stayed with USE for the
purposes of this discussion, because I want to get somewhere before
the all-important naming discussion starts).

- 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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Thread

Simple Strings JennyB <jennybrien@googlemail.com> - 2013-10-11 10:42 -0700
  Re: Simple Strings Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-11 21:05 +0200
    Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-11 15:49 -0700
      Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-11 16:21 -0700
        Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-11 16:28 -0700
        Re: Simple Strings mhx@iae.nl - 2013-10-12 01:03 -0700
        Re: Simple Strings albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-24 12:04 +0000
          Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-25 02:32 -0700
            Re: Simple Strings albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-25 11:43 +0000
              Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-25 06:03 -0700
    Re: Simple Strings hughaguilar96@yahoo.com - 2013-10-11 21:26 -0700
      Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-11 23:33 -0700
        Re: Simple Strings "WJ" <w_a_x_man@yahoo.com> - 2013-10-12 18:40 +0000
      Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-12 05:40 -0500
        Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-12 04:36 -0700
          Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-12 08:56 -0500
            Re: Simple Strings Howerd <howerdo@yahoo.co.uk> - 2013-10-12 14:04 -0700
              Re: Simple Strings Coos Haak <chforth@hccnet.nl> - 2013-10-13 01:04 +0200
                Re: Simple Strings Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-13 03:25 +0200
              Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-13 02:01 -0500
              Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-14 17:24 +0000
            Re: Simple Strings "Elizabeth D. Rather" <erather@forth.com> - 2013-10-12 11:40 -1000
              Re: Simple Strings Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-13 00:53 +0200
              Re: Simple Strings hughaguilar96@yahoo.com - 2013-10-12 22:13 -0700
              Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-13 02:16 -0500
                Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-15 14:57 +0000
                Re: Simple Strings Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-15 19:45 +0200
              Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-14 17:27 +0000
                Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-14 20:14 +0100
                Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-15 16:06 +0000
            Re: Simple Strings Paul Rubin <no.email@nospam.invalid> - 2013-10-13 20:58 -0700
              Re: Simple Strings m.a.m.hendrix@tue.nl - 2013-10-14 00:00 -0700
              Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 03:18 -0500
                Re: Simple Strings Paul Rubin <no.email@nospam.invalid> - 2013-10-14 01:49 -0700
                Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 04:29 -0500
                Re: Simple Strings m.a.m.hendrix@tue.nl - 2013-10-14 03:01 -0700
                Re: Simple Strings Roelf Toxopeus <rt4all@notthis.hetnet.nl> - 2013-10-14 15:09 +0200
                Re: Simple Strings Paul Rubin <no.email@nospam.invalid> - 2013-10-14 03:26 -0700
                Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 09:21 -0500
                Re: Simple Strings Graham Smith <"s\" xyzgrahams@tectime.com\" 3 /string"> - 2013-10-14 17:49 +0100
                Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 12:53 -0500
                Re: Simple Strings "Elizabeth D. Rather" <erather@forth.com> - 2013-10-14 09:26 -1000
                Re: Simple Strings albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-28 18:19 +0000
              Re: Simple Strings Roelf Toxopeus <rt4all@notthis.hetnet.nl> - 2013-10-14 11:02 +0200
              Re: Simple Strings Marc Olschok <nobody@nowhere.invalid> - 2013-10-15 14:43 +0000
                Re: Simple Strings albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-15 15:59 +0000
                Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-16 12:12 +0000
                Re: Simple Strings albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-10-17 11:52 +0000
          Re: Simple Strings "Alex McDonald" <blog@rivadpm.com> - 2013-10-12 16:55 +0100
      Re: Simple Strings Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-12 16:12 +0200
        Re: Simple Strings "Alex McDonald" <blog@rivadpm.com> - 2013-10-12 16:50 +0100
          Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-14 09:41 +0100
            Re: Simple Strings "Alex McDonald" <blog@rivadpm.com> - 2013-10-14 13:10 +0100
              Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-14 13:46 +0100
                Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 09:23 -0500
                Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-14 17:38 +0100
                Re: Simple Strings Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-10-14 12:56 -0500
                Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-14 20:33 +0100
                Re: Simple Strings "Alex McDonald" <blog@rivadpm.com> - 2013-10-14 21:50 +0100
                Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-14 22:29 +0100
                Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-14 22:31 +0100
                Re: Simple Strings "Alex McDonald" <blog@rivadpm.com> - 2013-10-14 22:46 +0100
              Re: Simple Strings Lars Brinkhoff <lars.spam@nocrew.org> - 2013-10-15 08:00 +0200
                Re: Simple Strings Lars Brinkhoff <lars.spam@nocrew.org> - 2013-10-15 13:20 +0200
                Re: Simple Strings Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2013-10-15 13:36 +0100
                Re: Simple Strings Lars Brinkhoff <lars.spam@nocrew.org> - 2013-10-16 12:11 +0200
                Re: Simple Strings Coos Haak <chforth@hccnet.nl> - 2013-10-16 17:36 +0200
                Re: Simple Strings "Alex McDonald" <blog@rivadpm.com> - 2013-10-16 17:01 +0100
                Re: Simple Strings Lars Brinkhoff <lars.spam@nocrew.org> - 2013-10-16 20:52 +0200
  Re: Simple Strings "Clyde W. Phillips Jr." <cwpjr02@gmail.com> - 2013-10-12 22:49 -0700
    Re: Simple Strings hughaguilar96@yahoo.com - 2013-10-13 10:31 -0700
  Re: Simple Strings hughaguilar96@yahoo.com - 2013-10-13 10:30 -0700
  Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-14 16:26 +0000
    Re: Simple Strings JennyB <jennybrien@googlemail.com> - 2013-10-15 07:36 -0700
      Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-16 16:05 +0000
        Re: Simple Strings Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-16 19:58 +0200
          Re: Simple Strings Brad Eckert <hwfwguy@gmail.com> - 2013-10-29 07:40 -0700
            Re: Simple Strings Bernd Paysan <bernd.paysan@gmx.de> - 2013-10-29 17:10 +0100
              Re: Simple Strings Brad Eckert <hwfwguy@gmail.com> - 2013-10-29 16:39 -0700
            Re: Simple Strings anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-10-30 12:00 +0000

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