note davebaker I'm trying to better understand the Schwartzian Tranform (sorting a list by computable field). I've read the explanation in the Perl Cookbook, 2d ed. recipe 4.16. I also enjoyed <a href="http://www.stonehenge.com/merlyn/UnixReview/col06.html">Randal's 1996 article in the Unix Review</a>, which describes a sortable-hash technique before it goes on to show the map-sort-map transform technique. The sortable-hash technique intrigues me. Other than coolness and nicer-looking code, what is the advantage of this: <code> my @output = map { $_->[0] } sort { $a->[1] cmp $b->[1] } map { [$_, expensive_func($_)] } @input;</code> over this: <code> foreach $_ (@input) { $result_for{$_} = expensive_func($_); } my @output = sort { $result_for{$a} cmp $result_for{$b} } @input;</code> 9108 9108