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Groups > comp.lang.forth > #9427

Sets in Forth

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Part of a recent project was to generate the numbers 1-24 in random 
order.  One tack is to:
1) Initialize an "array" of 24 bytes to 0
2) For each of 24 times
    a) Get a random number between 0 and
       (the number of possible numbers - 1)
    b) Look at the array of available numbers using this position number
    c) If the number in that position is already chosen, go back to a)
    d) Otherwise,
        i) Mark the number as chosen
       ii) Move it to an array of chosen numbers

In my workday language, instead of searching among an array of available 
numbers until I found one, which had not already been chosen, I would 
use a set of available numbers and when one was chosen, I would simply 
delete it from the set.  Thus I would not go over the chosen numbers 
more than once.

Is there a way to create a set in Forth?  Of course, there is.  I could 
do it with a linked list and when a number is chosen, simply reorient 
the links to/from it, essentially removing it from the list.

Is there another or better way?


Thanks, Steve

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Sets in Forth Steve Graham <jsgrahamus@yahoo.com> - 2012-02-07 08:25 -0700
  Re: Sets in Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-02-07 15:44 +0000
    Re: Sets in Forth Steve Graham <jsgrahamus@yahoo.com> - 2012-02-07 09:49 -0700
    Re: Sets in Forth Paul Rubin <no.email@nospam.invalid> - 2012-02-07 19:24 -0800
  Re: Sets in Forth mhx@iae.nl (Marcel Hendrix) - 2012-02-07 22:12 +0200

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