I would like to sort a hash not in any of the ways I have seen in tutorials (therefore I am open to advice on rethinking the problem too). I need to sort these keys, in this order:

• start
• stop
• step

sort() on these strings will obviously return: start, step, stop, without my own sorting function. I have read japhy's Resorting to Sorting article and have attempted to apply some of those approaches, but I need a hand.

use strict;
use warnings;
use diagnostics;

my @aoh;
    push @aoh, {
        "start" => .4,
        "stop" => .6,
        "step" => .1 
    };
    push @aoh, {
        "start" => .3,
        "stop" => .5,
        "step" => .1
    };
    push @aoh, {
        "start" => .0,
        "stop" => .2,
        "step" => .1
    };
    push @aoh, {
        "start" => .5,
        "stop" => .7,
        "step" => .1
    };
my $aoh = \@aoh;

for my $point ( @{$aoh}) {
    #for my $type ( sort keys %$point ) {
    for my $type ( sort by_pref keys %$point ) {
        print "$type\t";
    }
    print "\n";
}

sub by_pref {
    $a cmp $b;
    #advice?
}
[download]

P.S. I am not interested in forcing the insertion order using Tie::IxHash for a few different reasons.