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From: ok@cs.mu.oz.au (Richard O'Keefe)
Newsgroups: comp.os.minix
Subject: Re: gotos
Message-ID: <2294@munnari.oz.au>
Date: 4 Oct 89 08:46:22 GMT
References: <24962@louie.udel.EDU> <1989Sep29.183703.1275@utzoo.uucp> <1989Oct3.131847.15627@ntvax.uucp>
Sender: news@cs.mu.oz.au
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In article <1989Oct3.131847.15627@ntvax.uucp>, jbeard@ntvax.uucp (Jeff Beardsley) writes:
> Actually even the use of goto for a multi-level break/continue can easily
> be avoided by taking the entire multi-level structure, making it into a 
> function of its own, and using return.

> This gets rid of the goto statement needed for multi-level break as well
> as making the code more readable.  Therefore I believe the NO-GOTO blanket
> statement *IS* a defensible position.

The snag with this is that every variable which the formerly embedded
structure shared with its containing function now becomes a global
variable.  (In Pascal, "global" with respect to the new function; in
C, "global" in the sense of not local to any function, though perhaps
local to the file.)  You should be aware that global variables are a
maintenance problem in themselves; trading one goto for five globals
is rather like bending down to pick up 10 cents and dropping a dollar.

The answer is not to insert a goto and then patch it out by one or another
even more dubious dodge, but to follow a design method (such as the one
described by Dijkstra, Feijen, Gries, and others) where you never need a
goto or a multilevel loop exit in the first place.