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From: emv@ox.com (Ed Vielmetti)
Newsgroups: comp.lang.perl
Subject: Re: associative arrays of arrays
Message-ID: <EMV.91Feb21123130@poe.aa.ox.com>
Date: 21 Feb 91 20:31:30 GMT
References: <1991Feb21.051208.21101@mlb.semi.harris.com>
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In-Reply-To: jdr@sloth.mlb.semi.harris.com's message of 21 Feb 91 05:12:08 GMT

In article <1991Feb21.051208.21101@mlb.semi.harris.com> jdr@sloth.mlb.semi.harris.com (Jim Ray) writes:

   I would like to build an associative array which in turn points to
   lists ( one per key ).

   $array{$name} = SOME LIST

	   Where SOME LIST is some array ( list ) of indices into another set
	   of arrays containing relivant record information.  This array
	   would be periodically added to while traversing the entire
	   list of people.

What I have done for this (without perfect luck yet, I admit) is to
simply make the "SOME LIST" a space-delimited string of indexes.  When
you need to get the list out as a list you do a split on it, e.g.

$sets{"csound"} = "1990.03:123.Z 1990.06:105.Z 1991.02:3458.Z" ;
$sets{$name} .= " " . $key ;		# add a key
@keys = split(" ",$sets{$name}) ;	# get your list back

you'll probably want and, or, xor, sort, and uniq operators on these
things too.

--Ed