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From: jeenglis@nunki.usc.edu (Joe English)
Newsgroups: comp.lang.c
Subject: Re: Oh nooo! (gotos)
Message-ID: <4993@merlin.usc.edu>
Date: 8 Sep 89 01:04:45 GMT
References: <7598@goofy.megatest.UUCP> <12793@pur-ee.UUCP> <1461@atanasoff.cs.iastate.edu>
Sender: news@merlin.usc.edu
Reply-To: jeenglis@nunki.usc.edu (Joe English)
Organization: University of Southern California, Los Angeles, CA
Lines: 49

In article <1461@atanasoff.cs.iastate.edu> hascall@atanasoff.cs.iastate.edu.UUCP (John Hascall) writes:
>In article <12793@pur-ee.UUCP> lewie@ecn-ee.UUCP writes:
>}[...] the equivalent of a continue with a label, i.e.:
> 
>}while foo (...) {
>}    while (...) {
>}	...
>}	continue foo; 
>}	...
>}    }
>
>  I have often wished for something similar, my thoughts have tended toward
>  the synatx:
>
>	  continue [constant-integer-expression];
>	  break [constant-integer-expression];
>
>   where the [optional] expression indicated how many nested structures
>   to continue or break, with the default being 1 (just like the current
>   "continue" and "break").

Oog... I don't think that's such a good idea; it's
easier to look for a label than to count sets of braces --
and check that they belong to a while/for/do and not an
if.  Plus, if later on you move the code around, adding
or deleting loops, you can introduce errors that aren't
easy to spot.

>   While we are on the subject of loops, how do people feel about the
>   practice of using #define to "extend" the language?  For example:
>
>   #define loop     for (;;)
>   #define exitloop break

I'm against this in general, but I've seen it used
quite effectively in some cases for information hiding:

#define foo_iterate(idx,foo) for (idx=foo.items;idx<foo.lastitem;++idx)
...
       foo_iterate(i,qux) {
            ... use i ...
       }

Whether this makes things clearer or more obfuscated
is debatable.

--Joe English

  jeenglis@nunki.usc.edu