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Path: utzoo!utcs!mnetor!toram!chris
From: chris@toram.UUCP (Chris Robertson)
Newsgroups: net.lang.c
Subject: Re: An amusing piece of code
Message-ID: <134@toram.UUCP>
Date: Tue, 8-Apr-86 09:46:33 EST
Article-I.D.: toram.134
Posted: Tue Apr  8 09:46:33 1986
Date-Received: Tue, 8-Apr-86 12:42:39 EST
References: <1370@ism780c.UUCP>
Reply-To: chris@toram.UUCP (Chris Robertson)
Organization: Toram/Globe-Tek Systems Ltd., Toronto, Canada
Lines: 50
Summary: 

In article <1370@ism780c.UUCP> tim@ism780c.UUCP (Tim Smith) writes:
>Here is an amusing piece of code ...  that, if written with if-then-else
>would be
>
>	if ( thing == A )
>		A-code;
>	else
>	if ( thing == B || thing == C || thing == D ) {
>		switch ( thing ) {
>	case B:         B-code; break;
>	case C:         C-code; break;
>	case D:         D-code; break;
>		}
>		BCD-common-code;
>	} else
>	if ( thing == E )
>		E-code;
>
>A, B, C, D, and E are constant expressions, so this is not elegant.
>We would like to use a switch for everything.  Here is a solution:
>
	[ VERY inelegant switch code deleted ]

Why not just use:

	BCD-flag=FALSE;
	if (thing == A)
		A-code;
	else if (thing == E)
		E-code;
	else {
		switch (thing) {
			case B:
				B-code;BCD-flag=TRUE;break;
			case C:
				C-code;BCD-flag=TRUE;break;
			case D:
				D-code;BCD-flag=TRUE;break;
		}
		if (BCD-flag)
			BCD-common-code;
	}

This tests all your stuff, in a fairly straightforward way, and only costs
1 measly flag.
-- 

	Christine Robertson  {ihnp4,linus,decvax}!utzoo!toram!chris

	An apple a day keeps the doctor away, especially if aimed well.