Path: utzoo!attcan!uunet!decwrl!ucbvax!iwarp.intel.com!news
From: merlyn@iwarp.intel.com (Randal Schwartz)
Newsgroups: comp.lang.perl
Subject: Re: Ordering one array by another
Message-ID: <1990Mar27.161630.16724@iwarp.intel.com>
Date: 27 Mar 90 16:16:30 GMT
References: <8251@ogicse.ogi.edu>
Sender: news@iwarp.intel.com
Reply-To: merlyn@iwarp.intel.com (Randal Schwartz)
Organization: Stonehenge; netaccess via Intel, Beaverton, Oregon, USA
Lines: 39
In-Reply-To: schaefer@ogicse.ogi.edu (Barton E. Schaefer)

In article <8251@ogicse.ogi.edu>, schaefer@ogicse (Barton E. Schaefer) writes:
| I have a sorted list of keywords, and a file (well, stdin actually, but
| no matter) consisting of lines each of which contains at most one of the
| keywords.  There may be keywords not in the file, and lines with zero
| keywords (which are ignored), but no pair of lines both contain the same
| keyword.  What I want to do is reorder the input lines to match the order
| in the list of keywords.
| 
| So what's the fastest way?  What I have right now goes like this:
| 
|     @lines = <STDIN>;				# Whomp it in
|     # Never mind how I got the sorted keywords, they're in @keys
|     foreach $k (@keys) {			# For every keyword
| 	$i = $[;				# Reset the index
| 	foreach $l (@lines) {			# For every line
| 	    if ($l =~ /\b$k\b/) {		# If it matches
| 		print splice(@lines,$i,1);	# Remove and print it
| 		last;				# Done with this pass
| 	    }
| 	    $i++;				# Increment index
| 	}
|     }

Too much newfangled technology.  Do it easy...

	$_ = "\n" . join("",<STDIN>); # slurrrrpp...
	for $k (@keys) {
		s/(\n)(.*\b$k\b.*\n)/print($2),$1/eg;
			# don't discard the previous newline "$1"
	}
	# at this point, $_ has "\n" followed by anything left...
	s/^\n//; print;

@p=split(//,",rekcah lreP rehtona tsuJ");p:print pop(p);goto p if @p;
-- 
/=Randal L. Schwartz, Stonehenge Consulting Services (503)777-0095 ==========\
| on contract to Intel's iWarp project, Beaverton, Oregon, USA, Sol III      |
| merlyn@iwarp.intel.com ...!any-MX-mailer-like-uunet!iwarp.intel.com!merlyn |
\=Cute Quote: "Welcome to Portland, Oregon, home of the California Raisins!"=/