Path: utzoo!utgpu!watmath!iuvax!purdue!mentor.cc.purdue.edu!pur-ee!lewie
From: lewie@pur-ee.UUCP (Jeff Lewis)
Newsgroups: comp.lang.c
Subject: Re: Oh nooo! (gotos)
Message-ID: <12793@pur-ee.UUCP>
Date: 6 Sep 89 19:02:38 GMT
References: <7598@goofy.megatest.UUCP>
Reply-To: lewie@ecn-ee.UUCP
Organization: Purdue University Robot Vision Lab
Lines: 35

[Dave Jones offers an example of what he thinks is a valid use of goto]:
[code trimmed to get to the meat]

>  while(rule = (Rule*)Queue_iter_next(&rule_iter)) {
>    
>    while(rsym = (Symbol*)Queue_iter_next(&rsym_iter)) {
>	switch (derives(rsym)) {
>	case derives_nothing:
>	  goto next_rule;
>	....
>	}
>    }
>    
>  next_rule: continue;
>    
>  }

I'm sure this comes up often enough, but the reason I'd say there's nothing
wrong with this type of goto is that it is the equivalent of a continue
with a label, i.e.:

while foo (...) {
    while (...) {
	...
	continue foo; 
	...
    }
}
('foo' is a loop label, which can be used within the loop's scope to alter
flow of control via break or continue)

This, I would say, is just as structured as the simple 'break' and 'continue'
that I presume most people have no problem with.  Of course C doesn't offer
this obvious functionality, so you fake it with the occasional 'goto'.  Is
there anything wrong with this?