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Re: The extended Eaker-Pelc CASE as general control structure

From "WJ" <w_a_x_man@yahoo.com>
Newsgroups comp.lang.forth
Subject Re: The extended Eaker-Pelc CASE as general control structure
Date 2016-02-11 19:45 +0000
Organization A noiseless patient Spider
Message-ID <n9ioc0$6dk$1@dont-email.me> (permalink)
References <2016Feb6.191548@mips.complang.tuwien.ac.at> <n98pmj$1lca$2@gioia.aioe.org> <2016Feb8.121100@mips.complang.tuwien.ac.at> <n9i5hl$nki$1@dont-email.me>

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WJ wrote:

> Anton Ertl wrote:
> 
> > 
> > : collatz ( u -- )
> >   begin
> >     begin
> >       dup .
> >       dup 1 = if
> >         drop exit then
> >       dup 1 and while
> >         3 * 1+
> >     repeat
> >     2/
> >   again ;
> 
> Oforth:
> 
> : collatz(n)
>   n .
>   n 2 < ifTrue: [return]
>   n n isOdd ifTrue: [3 * 1+] else: [2 /]
>   collatz ;
> 
> 33 collatz
> 
> 33 100 50 25 76 38 19 58 29 88 44 22 11 34 17 52 26 13 40 20 10 5 16 8 4 2 1 ok

Which 2-digit number produces the longest Collatz sequence, and
how long is that sequence?

Oforth:

: collatz-length(n,len)
  n 2 < ifTrue: [len return]
  n n isOdd ifTrue: [3 * 1+] else: [2 /]
  len 1+ collatz-length ;

seqFrom(2,99) map(#[dup 1 collatz-length [,]]) maxFor(#last) .
 ===>
[97, 119] ok

-- 
Amazon bans book.  After nearly a month on the site, all traces of the book and
its 80 reviews have been removed.
http://jamesfetzer.blogspot.com/2015/11/debunking-sandy-hook-debunkers-5.html
https://www.youtube.com/watch?v=EEl_1HWFRfo

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The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-06 18:15 +0000
  Re: The extended Eaker-Pelc CASE as general control structure JennyB <jennybrien@googlemail.com> - 2016-02-07 03:57 -0800
    Re: The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-08 12:59 +0000
      Re: The extended Eaker-Pelc CASE as general control structure JennyB <jennybrien@googlemail.com> - 2016-02-08 09:48 -0800
        Re: The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-08 18:10 +0000
          Re: The extended Eaker-Pelc CASE as general control structure JennyB <jennybrien@googlemail.com> - 2016-02-09 14:02 -0800
            Short-circuit evaluation (was: The extended Eaker-Pelc CASE ...) anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-10 16:10 +0000
  Re: The extended Eaker-Pelc CASE as general control structure "WJ" <w_a_x_man@yahoo.com> - 2016-02-07 14:32 +0000
  Re: The extended Eaker-Pelc CASE as general control structure "WJ" <w_a_x_man@yahoo.com> - 2016-02-07 14:53 +0000
    Re: The extended Eaker-Pelc CASE as general control structure Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-02-07 15:56 +0000
      Re: The extended Eaker-Pelc CASE as general control structure stephen@mpeforth.com (Stephen Pelc) - 2016-02-07 18:11 +0000
        Re: The extended Eaker-Pelc CASE as general control structure "HAA" <someone@microsoft.com> - 2016-02-08 12:04 +1100
          Re: The extended Eaker-Pelc CASE as general control structure stephen@mpeforth.com (Stephen Pelc) - 2016-02-08 10:29 +0000
            Re: The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-08 11:00 +0000
              Re: The extended Eaker-Pelc CASE as general control structure stephen@mpeforth.com (Stephen Pelc) - 2016-02-08 12:28 +0000
                Re: The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-08 15:26 +0000
                Re: The extended Eaker-Pelc CASE as general control structure stephen@mpeforth.com (Stephen Pelc) - 2016-02-08 16:16 +0000
                Re: The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-08 16:37 +0000
                Re: The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-08 16:21 +0000
            Re: The extended Eaker-Pelc CASE as general control structure "HAA" <someone@microsoft.com> - 2016-02-11 21:12 +1100
              Re: The extended Eaker-Pelc CASE as general control structure stephen@mpeforth.com (Stephen Pelc) - 2016-02-11 10:46 +0000
      Re: The extended Eaker-Pelc CASE as general control structure JennyB <jennybrien@googlemail.com> - 2016-02-07 12:33 -0800
        Re: The extended Eaker-Pelc CASE as general control structure stephen@mpeforth.com (Stephen Pelc) - 2016-02-08 10:38 +0000
  Re: The extended Eaker-Pelc CASE as general control structure "HAA" <someone@microsoft.com> - 2016-02-08 12:07 +1100
    Re: The extended Eaker-Pelc CASE as general control structure anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-02-08 11:11 +0000
      Re: The extended Eaker-Pelc CASE as general control structure Albert van der Horst <albert@spenarnc.xs4all.nl> - 2016-02-08 14:49 +0000
      Re: The extended Eaker-Pelc CASE as general control structure "HAA" <someone@microsoft.com> - 2016-02-09 20:31 +1100
        Re: The extended Eaker-Pelc CASE as general control structure hughaguilar96@gmail.com - 2016-02-09 12:38 -0800
      Re: The extended Eaker-Pelc CASE as general control structure "WJ" <w_a_x_man@yahoo.com> - 2016-02-11 14:23 +0000
        Re: The extended Eaker-Pelc CASE as general control structure "WJ" <w_a_x_man@yahoo.com> - 2016-02-11 19:45 +0000

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