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From: mirk@warwick.UUCP (Mike Taylor)
Newsgroups: misc.misc,comp.misc
Subject: The "evil" GOTO (Was: 25 Years of BASIC)
Summary: It ain't *that* bad
Keywords: Guinness, phlegm, mackerel, intestines
Message-ID: <1814@ubu.warwick.UUCP>
Date: 4 May 89 13:12:14 GMT
References: <1791@ubu.warwick.UUCP> <1436@onion.reading.ac.uk>
Sender: news@warwick.UUCP
Reply-To: mirk@uk.ac.warwick.cs (Mike Taylor)
Organization: Computer Science, Warwick University, UK
Lines: 56

In article <3, I think> gould@rosemary.cs.reading.ac.uk (Adrian Gould) writes:
> Lets eradicate the GOTO from all languages.

I hate it when people say things like that; As if you can just wave a
magic wand over a language by excising GOTO, and everything will be
alright.  Listen, just 'cause Quiche-eater Wirth connected GOTOs with
lack of structure geenrally, doesn't mean either that (A) ALL use of
GOTO is unstructured and obfuscatory, or that (B) ALL obfuscated code
is due to use of GOTO -- so why is it that so many people seem to
believe these myths?

How many times have you seen this kind of code?

	printf ("Enter your sex: ");
	while (sex != "m" && sex != "f") {
		gets (sex);
		if  (sex != "m" && sex != "f")
			printf ("<m> or <f> only: ");
	}

Why make the test twice?  Huh?  Huh?  Answer me that, all you obsessed
anti-GOTO campaigners.  The *natural* way to express the above is:

	printf ("Enter your sex: ");
LABEL:	gets (sex);
	if (sex != "m" && sex != "f") {
		printf ("<m> or <f> only: ");
		GOTO LABEL;
	}

Better examples abound, but in time honoured way, elude me now that I
need them.  How many times have you seen people using "for (;;;) ...
break;" when you *know* that by "break" they mean "GOTO"?  In many
situations GOTO is natural - the response of a thinking being to it is
to traid to know when those times are.  Clearly irresponsible use of
GOTO is bad; clearly spaghetti-junction programs written in languages
with no other flow-control are bad (Frog knows how APL people manage!)
But let's get this in perspective.  It isn't GOTO's fault.  It's yours
for using it badly.

It makes me laugh when people push Ada as a good real-time langauge
because iof its "powerful exception-handling".  "Exception-handling".
Do you know what that means?  Yup, you guessed it, it's a fancy word
for GOTO.  Luverly, Eh?  Dress it up to look nice'n'respectable,
install it as a fabulous feature in a DoD-sponsored langauge-to-end-
all-languages, and everyone loves it.  Well they ain't fooling me.
I know goto when I see it.

The reason Ada seems more powerful for having GOTO is simply because
the programming paradigm that is pushed together with Ada causes the
programmer to use GOTO in a disciplined way.  THAT is the answer to
the GOTO problem.  Teach people to recognise WHEN to use it, and teach
them to know HOW to use it.
______________________________________________________________________________
Mike Taylor - {Christ,M{athemat,us}ic}ian ...  Email to: mirk@uk.ac.warwick.cs
Unkle Mirk sez: "G G7/B C F G G7/B B7 Em; Dm7 G7/B C Gdim7 G D C Gdim7 G D Cm"