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From: rbj@icst-cmr (Root Boy Jim)
Newsgroups: net.lang.c
Subject: Re:  An amusing piece of code
Message-ID: <2449@brl-smoke.ARPA>
Date: Mon, 7-Apr-86 16:13:15 EST
Article-I.D.: brl-smok.2449
Posted: Mon Apr  7 16:13:15 1986
Date-Received: Thu, 10-Apr-86 00:42:59 EST
Sender: news@brl-smoke.ARPA
Lines: 61


	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
	
Great! You also discovered how to remove all break's from swithces too!
But this method will comlain about non-conditional conditionals as well.
I can recommend several solutions in my order of preference:

	1) Use Goto's. After case B & C, goto BCD-common

	2) Use a flag:
		flag = 0;
		switch(thing) {
		case A: A-code; break;
		case B: B-code; ++flag; break;
		case C: C-code; ++flag; break;
		case D: D-code; ++flag; break;
		case E: E-code; break;
		} if (flag) BCD-code;

	3) If the switch is isolated in it's own function:
		switch(thing) {
		case A: A-code; return;
		case B: B-code; ++flag; break;
		case C: C-code; ++flag; break;
		case D: D-code; ++flag; break;
		case E: E-code; return;
		} BCD-code;
		
	4) Use a switch within a switch
		switch(thing) {
		case A: A-code; break;
		case B: 
		case C: 
		case D: switch(thing) {
			case B: B-code; break;
			case C: C-code; break;
			case D: D-code; break;
			} BCD-code;
			break;
		case E: E-code; break;
		}
	...
	99) Use your solution

	(Root Boy) Jim Cottrell		<rbj@cmr>