Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!hplabs!hpl-opus!hpnmdla!chrise
From: chrise@hpnmdla.hp.com (Chris Eich)
Newsgroups: comp.lang.perl
Subject: Re: Sortin based on part of an associative array?
Message-ID: <8310026@hpnmdla.hp.com>
Date: 15 Apr 91 23:42:17 GMT
References: <17524@venera.isi.edu>
Organization: HP Network Measurements Div, Santa Rosa, CA
Lines: 31

In comp.lang.perl, tchrist@convex.COM (Tom Christiansen) writes:

    sub sort_by_field {
	local(*table, $field) = @_;
	local($_, @keys);
	for (keys %table) {
	    push(@keys, (split(/#/, $table{$_}))[$field]);
	} 
	sort bynum @keys;
    } 

    @Images{&sort_by_len} is all the elements in length order; 
    @Images{&sort_by_wid} is all the elements in width order.

This doesn't seem to work; sort_by_len returns the lengths, not the keys
of the original table.

You seem to want sort_by_field to return the keys of the original table,
so how about this:

    sub sort_by_field {
	local(*Table, $Field) = @_;
	local(%Keys);

	foreach (keys %Table) {
	    $Keys{(split(/:/, $Table{$_}))[$Field]} = $_;
	}
	@Table{@Keys{sort by_num keys %Keys}};
    }

Chris