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Path: utzoo!utcsri!greg
From: greg@utcsri.UUCP (Gregory Smith)
Newsgroups: net.lang.c
Subject: Re: What should be added to C
Message-ID: <2834@utcsri.UUCP>
Date: Sat, 24-May-86 21:44:00 EDT
Article-I.D.: utcsri.2834
Posted: Sat May 24 21:44:00 1986
Date-Received: Sat, 24-May-86 22:30:38 EDT
References: <1462@mmintl.UUCP> <5498@alice.uUCp> <1497@mmintl.UUCP>
Reply-To: greg@utcsri.UUCP (Gregory Smith)
Organization: CSRI, University of Toronto
Lines: 63
Summary: 

In article <1497@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes:
>
>>> o An andif clause for if statements.
>
>You would write:
>
>  if (A) {
>    X
>  } andif (B) {
>    Y
>  } else {
>    Z
>  }
>
>This is equivalent to:
>
>   if (!(A)) goto _Z;
>   X
>   if (B) {
>     Y
>   } else {
>_Z:
>     Z
>   }
>
Interesting - like a switch, but with dynamic conditions. How about
actually writing it like a switch:

	switch(){			/* or just 'switch{' */
		when A:	X;
			break;
		when B: Y;
			break;
		default:
			Z;
	}
A and B, are arbitrary expressions which are evaluated in sequence.
Sorry about stealing the extra keyword. Actually, 'case' would work just
as well; and it wouldn't really be confusing, since one type of switch
*must* have a constant exp and the other type would have to have
non-constant expressions in reasonable usage. This would be easy to
compile, and much more readable than an if..else.. etc.

>>> o Any sort of multi-level break statement.  There is no syntacticly clean
>>> way of adding this to C.

I don't agree.   what about
statement ::=	break ;
	|	break constant_exp ;

e.g.	break 2;
would break the current loop *and* the enclosing one.

Of course, you can obfuscate this with

#define BRKS 3;
...
	break BRKS;	/* ;-) */

-- 
"We demand rigidly defined areas of doubt and uncertainty!" - Vroomfondel
----------------------------------------------------------------------
Greg Smith     University of Toronto      UUCP: ..utzoo!utcsri!greg