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From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: goto's
Message-ID: <7796@mimsy.UUCP>
Date: Fri, 31-Jul-87 04:33:41 EDT
Article-I.D.: mimsy.7796
Posted: Fri Jul 31 04:33:41 1987
Date-Received: Sat, 1-Aug-87 16:05:05 EDT
References: <3289@bigburd.PRC.Unisys.COM> <7571@beta.UUCP> <765@haddock.ISC.COM> <105@rdlvax.UUCP>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 42

In article <105@rdlvax.UUCP> kopaz@rdlvax.UUCP (John Anthony 'Echo'
Kopaz) writes:
[regarding mechanically removing goto statements by adding booleans]
>i don't think all that warped boolean logic is in the best interest to 
>readable code.

Certainly not.  But someone made the claim that there are algorithms
that require goto statements; this is not the case.  On the other hand,
modern imperative languages have all the constructs they do for good
reason:  You can write what you mean.

Clear code requires two things: knowing what you mean; and writing
that.  If you *really mean* `go do something special', by all means,
write that.  But if you mean something that can be expressed *simply*
(this is important) using a weaker construct (`weaker' here means
`less able to affect control flow': `while' is weaker than `goto'),
use the weaker form.  It says less, and hence is easier to understand.

A loop that reads

	while ((in = getinput()) != END_OF_INPUT)
		(*op[in])(in);

is using a very strong control operation, yet may well be easier to
understand than a whole series of weak `if's:

	while ((in = getinput()) != END_OF_INPUT) {
		if (in < 4) {
			...
		} else if (in == 4) {
			...
		} else if (in < 7) {
			...
		} ...
	}

Deciding when the stronger construct makes the code clearer is an
art, and different people will certainly have different aesthetics.
So what else is new? :-)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
Domain:	chris@mimsy.umd.edu	Path:	seismo!mimsy!chris