#! perl -slw use strict; use Date::Calc qw(Decode_Date_US); use Data::Dumper; use Benchmark qw[ cmpthese ]; sub convertdate { return sprintf '%04d%02d%02d', Decode_Date_US( $_[0] ) } our @list = ( { fname => 'Jan', lname => 'Krynicky', birth_date => 'Sep 3 1975', }, { fname => 'Pavel', lname => 'Krynicky', birth_date => 'Dec 25 1969', }, { fname => 'Martin', lname => 'Krynicky', birth_date => 'Aug 24 1973', }, map{ { fname => $_, lname => 'Krynicky', birth_date => 'Jan 1 ' . ( 1900 + int( rand 100 ) ) } } 1 .. $ARGV[ 0 ] || 100 ); cmpthese -1, { ST => q[ my @sorted = map{ $_->[1] } sort{ $a->[0] <=> $b->[0] } map{ [ convertdate($_->{birth_date}), $_ ] } @list; ], KEY => q[ { my @keys = map convertdate($_->{birth_date}), @list; @sorted = @list[ sort {$keys[$a] cmp $keys[$b]} (0..$#list) ]; } ], GRTish => q[ my @sorted = @list[ map { substr( $_, 8 ) } sort map { convertdate( $list[$_]->{birth_date} ) . $_ } 0 .. $#list ]; ], };