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From: chandros@topaz.RUTGERS.EDU (Chandros)
Newsgroups: net.lang.c
Subject: Good code for sometimes shared case stuff
Message-ID: <4695@topaz.RUTGERS.EDU>
Date: Tue, 8-Apr-86 14:18:59 EST
Article-I.D.: topaz.4695
Posted: Tue Apr  8 14:18:59 1986
Date-Received: Thu, 10-Apr-86 20:32:27 EST
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 54
Keywords: case,shared,evil,goto


/* you have found a food				*/

I just started reading this group regularly, sof please forgive me if I'm
repeating something that was already said.

David Linn suggests the following as a solution to the "shared code in a
switch some of the time" problem. (I removed the goto version
for the benefit of the younger readers.  Shame, shame, shame on you.  
Evil gotos, gasp, and in C no less, what will the world think of next. )

>In posting<1370@ism780c.UUCP>, Tim Smith asks about a switch with common
>code for some cases. I have seen two solutions.
>1) put the common code in a subroutine
>        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; break;
>        }

> [evil goto version was here]

You forgot your structured programming rules.  What about a (here it comes
folks) a BOOLEAN variable called do_bcd_stuff??  Also, you could
set do_bcd_stuff to be true in the declaration, and only change it in the
case E to be false.  Anyway, that's unimportant.  I don't ken enough 
C to be sure, but it seems to me that the do_bcd_stuff declaration could
go inside the switch along with the if statement.  But I'm not sure, and
the following will work for sure.  (I hope, otherwise, BOY did I just made a
fool out of myself............)

ex:
	int do_bcd_stuff;
	switch(thing) {
		case A: A-code; do_bcd_stuff=TRUE; break;
		case B: B-code; do_bcd_stuff=TRUE; break;
		case C: C-code; do_bcd_stuff=TRUE; break;
		case D: D-code; do_bcd_stuff=TRUE; break;
		case E: A-code; do_bcd_stuff=FALSE; break;
		}
	if (do_bcd_stuff)
		bcd stuff goes here;

This is much better than using those evil gotos, or paying the cost of
a subroutine call.  

Jonathan A. Chandross
allegra!topaz!chandros		(that's 1 s kids....)


"It is the little, pathetic attempts at Quality that kill...." -- R. M. Pirsig
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