Newsgroups: comp.lang.perl
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!convex!usenet
From: Tom Christiansen <tchrist@convex.COM>
Subject: Re: Line Formatter
Message-ID: <1991Jun03.192318.22640@convex.com>
Sender: usenet@convex.com (news access account)
Nntp-Posting-Host: pixel.convex.com
Reply-To: tchrist@convex.COM (Tom Christiansen)
Organization: CONVEX Software Development, Richardson, TX
References: <11304@bunny.GTE.COM>
Date: Mon, 03 Jun 1991 19:23:18 GMT
Lines: 48

From the keyboard of hhg1@harvey.gte.com (Hallett German):
:I know that this has been posted before to this group but I have
:misplaced my copy. Could someone please send me/post a program
:that takes
:comp.lang.perl 1000 1001
:comp.lang.perl 1001 1002
:
:and converts it to 
:  comp.lang.perl 1000 1002
:A method appropriate to larger files (5000-10000 records) would be
:appreciated.

There's a lot about the problem that I don't know yet.  For example, are
all the lines of the same group adjacent?  Do you always have continuous
numeric ranges?  If both these are true, the following snippet of code
appears to do what you want.  (This should not suffer from having a lot of
records.)

    while (<DATA>) {
	($group, $lo, $hi) = split;
	if ($group ne $oldgroup) {
	    print "$oldgroup $oldlo $oldhi\n"	if $oldgroup;
	    ($oldgroup, $oldlo, $oldhi) = ($group, $lo, $hi);
	} else {
	    if ($oldhi == $lo) {
		$oldhi = $hi;
	    } else {
		# not contiguous!! do what here?
	    } 
	} 
    } 
    print "$oldgroup $oldlo $oldhi\n"		if $oldgroup;
    __END__
    comp.lang.perl 1000 1001
    comp.lang.perl 1001 1002
    comp.lang.perl 1002 1007
    alt.sources 1 7
    alt.sources 7 9
    misc.sources 10 120


If this isn't precisely what you want, then hopefully it'll 
give an idea of how do to so.  

--tom
--
Tom Christiansen		tchrist@convex.com	convex!tchrist
	    "Perl is to sed as C is to assembly language."  -me