Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!decvax!tektronix!teklds!dadla!tekla!robertv
From: robertv@tekla.UUCP (Robert Vetter)
Newsgroups: net.lang.c
Subject: Re: An amusing piece of code
Message-ID: <487@tekla.UUCP>
Date: Sun, 6-Apr-86 18:36:57 EST
Article-I.D.: tekla.487
Posted: Sun Apr  6 18:36:57 1986
Date-Received: Mon, 21-Apr-86 04:30:55 EST
References: <1370@ism780c.UUCP>
Reply-To: robertv@tekla.UUCP (Robert Vetter)
Organization: Tektronix, Inc., Beaverton, OR.
Lines: 78

In article <1370@ism780c.UUCP> tim@ism780c.UUCP (Tim Smith) writes:
>Here is an amusing piece of code that someone who wants to remain
>annonymous invented.
>
>The situation is that we have something 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:
>
>	switch ( thing ) {
>case A:         A-code; break;
>case B:         B-code; if ( 0 ) {
>case C:         C-code; if ( 0 ) {
>case D:         D-code; }}
>		BCD-common-code; break;
>case E:         E-code;
>	}
>
>Noone here has been able to come up with a reasonable style for this.  The
>example above is not to bad, but if B-code, C-code, etc, are complicated,
>then it starts to get ugly.
>
>
>-- 
>
>Tim Smith       sdcrdcf!ism780c!tim || ima!ism780!tim || ihnp4!cithep!tim
>
>PS: I bet you were relieved that I didn't say you invented this, right Darryl?



	Why not : 


	switch ( thing ) {
            case A:         A-code;
                            break;

            case B:         B-code;
		            BCD-common-code();
                            break;

            case C:         C-code;
		            BCD-common-code();
                            break;

            case D:         D-code;
		            BCD-common-code();
                            break;

            case E:         E-code;
	}
	

	It's structured and readable.


Rob Vetter
(503) 629-1291
[ihnp4, ucbvax, decvax, uw-beaver]!tektronix!tekla!robertv

"Waste is a terrible thing to mind" - NRC
  (Well, they COULD have said it)