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Re: Request for comments on a first forth program

From Christian Kellermann <ckeen@necronomicon.my.domain>
Newsgroups comp.lang.forth
Subject Re: Request for comments on a first forth program
Date 2013-07-20 21:34 +0200
Organization A noiseless patient Spider
Message-ID <87li51ja97.fsf@necronomicon.my.domain> (permalink)
References <87wqomga80.fsf@pestilenz.org> <718e78ac-36e5-477c-a8dc-d0e52520a85f@googlegroups.com>

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Hi Alex,

Alex McDonald <blog@rivadpm.com> writes:

> On Friday, 19 July 2013 10:39:11 UTC+1, Christian Kellermann  wrote:
>> Dear group readers,
>> 
>> 
> [ snip ]
>
> Excellent stuff for a first attempt.
>
>> \ robot words
>> 2 constant #robots
>> \ robots occupy 3 cells: x y alive?
>> create robots #robots 3 * cells allot
>> : robot@ ( i -- x y ) 3 * cells robots + 2@ ;
>> : robot! ( x y i -- ) 3 * cells robots + 2! ;
>> : robot-alive ( b i -- )  3 * cells 2 cells + robots + ! ;
>> : robot-alive? ( i -- b ) 3 * cells 2 cells + robots + @ ;
>
>
> There's some factoring you could do here and elsewhere that would
> improve the clarity. This could be factored to
>
> \ robot words
> 2 constant #robots
> \ robots occupy 3 cells: x y alive?
> \ size of robot slot in cells
> 3 cells constant slot-size 
> \ offset of state
> 2 cells constant state-off
> create robots slot-size #robots * allot
> : robot-slot ( i -- slot )   slot-size * robots + ;
> : robot@ ( i -- x y )        robot-slot 2@ ;
> : robot! ( x y i -- )        robot-slot 2! ;
> : robot-state ( i -- state ) robot-slot state-off + ;
> : robot-alive ( b i -- )     robot-state ! ;
> : robot-alive? ( i -- b )    robot-state @ ;

In the end I have decided not to use this, as I thought that since these
4 words are the only ones touching the memory layout of the robots
buffer. If I would ever change it these 4 words would also have to
change. And just changing any one of these constants by itself makes no
sense, so I "inlined" it in the words.

Your version is of course easier to read.

> For consistency with your other names, robot-alive should be
> robot-alive!

True!

Thanks for your suggestions!

Christian

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Thread

Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-19 11:39 +0200
  Re: Request for comments on a first forth program Ron Aaron <rambamist@gmail.com> - 2013-07-19 13:04 +0300
    Re: Request for comments on a first forth program rickman <gnuarm@gmail.com> - 2013-07-19 12:43 -0400
  Re: Request for comments on a first forth program Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-19 05:28 -0500
  Re: Request for comments on a first forth program m.a.m.hendrix@tue.nl - 2013-07-19 03:56 -0700
    Re: Request for comments on a first forth program m.a.m.hendrix@tue.nl - 2013-07-19 04:00 -0700
    Re: Request for comments on a first forth program rickman <gnuarm@gmail.com> - 2013-07-19 12:51 -0400
      Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:28 +0200
        Re: Request for comments on a first forth program anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-07-22 15:43 +0000
          Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-24 20:00 -0700
            Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-25 10:37 +0200
              Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-26 00:00 -0700
                Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-26 09:34 +0200
                Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-07-25 21:40 -1000
                Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-27 20:16 -0700
                Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-29 10:09 +0200
                Re: Request for comments on a first forth program m.a.m.hendrix@tue.nl - 2013-07-29 04:14 -0700
                Re: Request for comments on a first forth program Andrew Haley <andrew29@littlepinkcloud.invalid> - 2013-07-29 07:49 -0500
                Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-07-29 15:32 -1000
                Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-31 17:50 -0700
                Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-31 13:23 +0200
                Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-31 18:05 -0700
                Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-08-01 12:53 +0200
                Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-08-01 09:58 -0500
                Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-08-01 20:42 -0700
                Re: Request for comments on a first forth program Brad Eckert <hwfwguy@gmail.com> - 2013-08-04 18:53 -0700
                Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-08-04 22:05 -0500
                Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-08-04 20:54 -0700
                Re: Request for comments on a first forth program Alex McDonald <blog@rivadpm.com> - 2013-08-05 05:50 -0700
                Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-08-05 22:14 +0200
                Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-08-06 21:11 -0700
                Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-08-01 01:04 -0500
    Re: Request for comments on a first forth program albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-07-19 18:06 +0000
      Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:31 +0200
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:24 +0200
      Re: Request for comments on a first forth program anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-07-22 15:32 +0000
  Re: Request for comments on a first forth program Alex McDonald <blog@rivadpm.com> - 2013-07-19 06:49 -0700
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:34 +0200
  Re: Request for comments on a first forth program Mark Wills <markrobertwills@yahoo.co.uk> - 2013-07-19 07:19 -0700
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:41 +0200
  Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-07-19 07:55 -1000
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:47 +0200
      Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-07-20 11:15 -1000
    Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-20 20:09 -0700
  Re: Request for comments on a first forth program "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2013-07-19 19:36 +0100
    Re: Request for comments on a first forth program albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-07-20 12:36 +0000
      Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:53 +0200
      Re: Request for comments on a first forth program Coos Haak <chforth@hccnet.nl> - 2013-07-21 02:02 +0200
        Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-07-20 17:18 -1000
      Re: Request for comments on a first forth program Ian Osgood <iano@quirkster.com> - 2013-07-23 16:07 -0700
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:48 +0200
  Re: Request for comments on a first forth program stephenXXX@mpeforth.com (Stephen Pelc) - 2013-07-20 12:18 +0000
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@necronomicon.my.domain> - 2013-07-20 21:57 +0200
      Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-07-20 11:24 -1000
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-22 15:53 +0200
      Re: Request for comments on a first forth program m.a.m.hendrix@tue.nl - 2013-07-22 08:06 -0700
        Re: Request for comments on a first forth program albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-07-22 19:35 +0000
          Re: Request for comments on a first forth program m.a.m.hendrix@tue.nl - 2013-07-23 00:41 -0700
          Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-23 12:00 +0200
            Re: Request for comments on a first forth program albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-07-23 12:10 +0000
              Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-23 14:19 +0200
              Re: Request for comments on a first forth program stephenXXX@mpeforth.com (Stephen Pelc) - 2013-07-24 09:27 +0000
            Re: Request for comments on a first forth program anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-07-23 13:44 +0000
  Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-20 20:02 -0700
    Re: Request for comments on a first forth program albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-07-21 03:36 +0000
      Re: Request for comments on a first forth program hughaguilar96@yahoo.com - 2013-07-20 22:28 -0700
        Re: Request for comments on a first forth program albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-07-21 10:31 +0000
    Re: Request for comments on a first forth program rickman <gnuarm@gmail.com> - 2013-07-20 23:41 -0400
  Re: Request for comments on a first forth program anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2013-07-22 15:36 +0000
  Re: Request for comments on a first forth program Lars Brinkhoff <lars.spam@nocrew.org> - 2013-07-23 12:22 +0200
    Re: Request for comments on a first forth program Christian Kellermann <ckeen@pestilenz.org> - 2013-07-23 13:44 +0200
      Re: Request for comments on a first forth program albert@spenarnc.xs4all.nl (Albert van der Horst) - 2013-07-23 12:26 +0000
    Re: Request for comments on a first forth program "Elizabeth D. Rather" <erather@forth.com> - 2013-07-23 07:10 -1000
    Re: Request for comments on a first forth program stephenXXX@mpeforth.com (Stephen Pelc) - 2013-07-24 09:30 +0000

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