Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!ihnp4!ptsfa!lll-lcc!ames!cit-vax!ll-xn!mit-eddie!uw-beaver!tektronix!sequent!mntgfx!franka
From: franka@mntgfx.UUCP
Newsgroups: comp.lang.c
Subject: Re: jump tables (was Re: Why no labelled loops?)
Message-ID: <550@franka.mntgfx.MENTOR.COM>
Date: Mon, 2-Mar-87 15:57:20 EST
Article-I.D.: franka.550
Posted: Mon Mar  2 15:57:20 1987
Date-Received: Thu, 5-Mar-87 20:24:39 EST
References: <1710@plus5.UUCP> <388@cognos.UUCP> <545@mntgfx.MENTOR.COM> <5626@mimsy.UUCP>
Reply-To: franka@mntgfx.UUCP (Frank A. Adrian)
Organization: Mentor Graphics, Beaverton, OR
Lines: 25

In article <5626@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
>In article <545@mntgfx.MENTOR.COM> franka@mntgfx.MENTOR.COM (Frank A.
>Adrian) writes:

>>Now for my pet peeve.
>(Well, *he* spells it right. :-) )
Thank you...

>>it is not any more hazardous than the goto statement itself,
>Not so!  The existing C `goto' can never change function contexts.
>Only `longjmp' has this power.  Label assignments, unless they are
>severely restricted, one can do non-local `goto's quite easily.
>This also means that the label type must carry around a lot of
>extra baggage, which has a tendency to destroy much of the efficiency
>you thought you were gaining.

Ah yes, the fly in the ointment.  I had for gotten about the nasty little
non-localities one can introduce with this feature.  I'd say just don't
let label arrays be passed or used non-locally, but this introduces another
non-orthogonal feature into the language and I hate non-orthogonal constructs
even more than the inconvenience of assembly code.  I'll "cry uncle" on this
one.

Frank Adrian
Mentor Graphics, Inc.