Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uflorida!haven!uvaarpa!mmdf
From: alfie%cs.warwick.ac.uk@nsfnet-relay.ac.uk (Nick Holloway)
Newsgroups: comp.lang.perl
Subject: Re: $1, $2 not being set - array/scalar context confusion?
Message-ID: <1990Mar23.120241.20340@uvaarpa.Virginia.EDU>
Date: 23 Mar 90 12:02:41 GMT
Sender: mmdf@uvaarpa.Virginia.EDU (Uvaarpa Mail System)
Reply-To: alfie%cs.warwick.ac.uk@nsfnet-relay.ac.uk
Organization: The Internet
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In comp.lang.perl, lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall) writes:
| It is a bug, and will be fixed in patch 16.  

It's nice to know that my brain hadn't fried, and that I was not
misunderstanding what should happen (and to hear the magic words "will
be fixed").

| By the way, I think you can simplify your routine a little:

I had thought I had seen smaller routines to do the job, but that was
before I became a perl addict. I can see how all three routines work,
but I think I prefer the 2nd (purely subjective - I have not let
matters like performance cloud the issue :-). My original version
allowed you to use either a space or comma to separate the terms (so 
"1 3 - 5" is the same as "1,3-5"), and to return an empty array upon
finding an error, so here is Larry's version 2 of expand with these
spliced back in. Cheers, Larry, for the smaller routine.

sub expand {
    local($tmp) = @_;
    $tmp =~ s/\s+([-,])\s+/\1/g;		# remove non-sep spaces
    $tmp =~ s/\s+/,/g;				# replace sep spaces with ","
    $tmp =~ s/(\d+)-(\d+)/join(',',$1..$2)/eg;	# perform range expansion
    if ( $tmp =~ /([^\d,])/ ) {			# check remainder is valid
	warn "bad character '$1' in expand\n";
	$tmp = "";				# all bets are off!
    }
    split(',',$tmp);				# split and return elements
}

--
Nick Holloway |  `O O'  | alfie@cs.warwick.ac.uk, alfie@warwick.UUCP,
[aka `Alfie'] | // ^ \\ | ..!uunet!mcsun!ukc!warwick!alfie