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Re: Strange results


From: Erich Neuwirth
Subject: Re: Strange results
Date: Sat, 7 Sep 2013 09:22:04 +0200

You need to learn about set and setq vs let

Von meinem iPad gesendet

Am 07.09.2013 um 09:06 schrieb Dwaddle <address@hidden>:

> Hi
> 
> i've been dabbling around in elisp for a while. Made this function
> 
> The issue is the byte var which 'remembers' the result from a previous 
> calculation.
> 
> (integer-bin 5)     [0 0 0 0 0 1 0 1]
> (integer-bin 3)     [0 0 0 0 0 1 1 1]
> 
> To beat the critics I know it isn't very clean programmed and a loop would 
> make it al lot shorter
> 
> <code>
> (defun integer-bin (dec)
>  "Convert integer to binairy"
>  (setq 8bit [128 64 32 16 8 4 2 1])
>  (setq byte [0 0 0 0 0 0 0 0])
>  (if (= 1 (/ dec (aref 8bit 0))) (when
>                                      (aset byte 0 1)
>                                      (setq dec (- dec 128))))
>  (if (< 0 dec)
>  (if (= 1 (/ dec (aref 8bit 1))) (when
>                                      (aset byte 1 1)
>                                      (setq dec (- dec 64)))))
>  (if (< 0 dec)
>  (if (= 1 (/ dec (aref 8bit 2))) (when
>                                      (aset byte 2 1)
>                                      (setq dec (- dec 32)))))
>  (if (< 0 dec)
>  (if (= 1 (/ dec (aref 8bit 3))) (when
>                                      (aset byte 3 1)
>                                      (setq dec (- dec 16)))))
>  (if (< 0 dec)
>  (if (= 1 (/ dec (aref 8bit 4))) (when
>                                      (aset byte 4 1)
>                                      (setq dec (- dec 8)))))
>  (if (< 0 dec)
>  (if (= 1 (/ d<ec (aref 8bit 5))) (when
>                                      (aset byte 5 1)
>                                      (setq dec (- dec 4)))))
>  (if (< 0 dec)
>  (if (= 1 (/ dec (aref 8bit 6))) (when
>                                      (aset byte 6 1)
>                                      (setq dec (- dec 2)))))
> (if (< 0 dec)
>  (if (= 1 1) (when (aset byte 7 1)
>                    (setq dec (- dec 1)))))
> (print byte)
> )
> </code> 



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