Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!jpl-devvax!lwall
From: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Newsgroups: comp.lang.perl
Subject: Re: Done already (was Re: referencing scalars apart from subroutine calls)
Message-ID: <7316@jpl-devvax.JPL.NASA.GOV>
Date: 7 Mar 90 18:44:04 GMT
References: <1232@frankland-river.aaii.oz.au> <1990Mar7.055852.1192@iwarp.intel.com>
Reply-To: lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 48

In article <1990Mar7.055852.1192@iwarp.intel.com> merlyn@iwarp.intel.com (Randal Schwartz) writes:
: In article <1232@frankland-river.aaii.oz.au>, pem@frankland-river (Paul E. Maisano) writes:
: | Hey, I just thought of one way: ;-)
: | 
: |     grep( do {
: | 		...	# refer to array element as $_
: | 		...
: | 	    },
: | 	$array[EXPR]
: | 	);
: 
: Arrggh!  grep() taken to the extreme!!!  This is better supported as:
: 
: for ($array[EXPR]) {
: 	...
: 	...
: 	...
: }
: 
: Same results exactly.  If you assign into $_, the corresponding array
: element changes (right, Larry?).

Sorry, no.  Only if you put the whole array in.  The above gets translated
internally to

	@_GEN_0 = ($array[EXPR]);
	for (@_GEN_0) {

: | Now if I could only name the variable something other than $_ ...
: 
: Presto magico:
: 
: for $something_other_than_dollar ($array[EXPR]) {
: 	...
: 	...
: 	...
: }
: 
: How's *that* for fast implementation?

Fast but still buggy.  :-)   But I'll admit it's real close to what he wants.

: $_="kheauroes ,rJttParn lhc e";srand(1);
: while($a=length){$a=rand($a);print(substr($_,$a,1));substr($_,$a,1)="";}

Also non-portable to non-31-bit rand() machines.

Larry