Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!uwm.edu!ogicse!emory!hubcap!billwolf%hazel.cs.clemson.edu
From: billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu (William Thomas Wolfe, 2847 )
Newsgroups: comp.lang.c
Subject: Re: problems/risks due to programming language
Message-ID: <8145@hubcap.clemson.edu>
Date: 25 Feb 90 00:42:57 GMT
References: <SUY1G_Fxds13@ficc.uu.net>
Sender: news@hubcap.clemson.edu
Reply-To: billwolf%hazel.cs.clemson.edu@hubcap.clemson.edu
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From peter@ficc.uu.net (Peter da Silva):
> On the other hand, the people (inlcuding Bill) arguing that switch...break
> is an unalloyed disaster are also all wet.  The C SWITCH is not a Pascal
> CASE, it's a computed goto:   [Fallthrough example]

   Which, amazingly enough, I explicitly noted in my original article:

     [...] In C, the case statement *requires* the
     use of a restricted GOTO in order to accomplish "normal" processing;
     at the end of the section of code processing a given case, one must
     use a restricted GOTO in order to prevent C from sending the flow of
     control straight into the section of code which was intended to process
     the NEXT case.  In other words, C requires the programmer to use a
     dangerous construct on a routine basis.

   Many (including Peter) have re-observed that this is the way C's switch
   currently operates, but to date nobody has provided any justification for
   having it continue to operate that way.  Apparently the thinking is that
   if the current definition is repeated often enough, it will be accepted
   regardless of how completely bizarre it is.  

   Given the fact that switch..break results in the generation of many
   unnecessary lines of "break" code, that it requires its users to get 
   into the habit of using a restricted GOTO to accomplish "normal" 
   processing (the expensive nature of this habit being dramatically 
   demonstrated by the recent nationwide AT&T crash), and that there 
   is a widely used (and considerably safer) alternative, it would seem 
   that C would be considerably better off if it were to either redefine 
   or replace its switch construct with a case statement.


   Bill Wolfe, wtwolfe@hubcap.clemson.edu

   P.S.  Pending this change, feel free to use Ada instead...  :^)