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From: pf@artcom0.north.de (Peter Funk)
Newsgroups: comp.lang.modula2
Subject: Re: Bitwise EXOR
Message-ID: <2299@artcom0.north.de>
Date: 1 Oct 90 11:12:14 GMT
References: <303.27024D31@puddle.fidonet.org>
Distribution: comp
Organization: ArtCom GmbH, Atelier f. Computergrafik, Bremen(FRG)
Lines: 28

Herman.Stevens@p21701.f601.n292.z2.fidonet.org (Herman Stevens) writes:
[...]
hs> ......... I fail to see how I can do a bitwise EXOR, something you
hs> can easily write in C as :

hs>          tmpbuf[i] = inbuf[i]^key[kp]

hs> Can someone help me on this ?

Bit-Operations are usually coded in Modula-2 using the Type BITSET:
Assume : VAR b1, b2, b3 : BITSET;

	b3 := b1 * b2;     <-->     b3 <- b1 AND b2;
	b3 := b1 + b2;     <-->     b3 <- b1 OR  b2;
	b3 := b1 - b2;     <-->     b3 <- b1 AND NOT b2;
	b3 := b1 / b2;     <-->     b3 <- b1 XOR b2;

So your problem may be solved typing :
	     tmpbuf [i] := yourType (BITSET(inbuf [i]) / BITSET(key [kp]));
where 'yourType' is the element data type of 'tmpbuf'.

Gruss, Peter
-->
Peter Funk \\ ArtCom GmbH, Schwachhauser Heerstr. 78, D-2800 Bremen 1
Work at home: Oldenburger Str.86, D-2875 Ganderkesee 1 /+49 4222 6018 (8am-6pm)
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