#!/usr/bin/perl -w
use strict;
my @things_to_sort = (
                   { author => 'bart', title => 'skateboarding' },
                   { author => 'lisa', title => 'postmodernism' },
                   { author => 'marge', title => 'hairstyles' },
                   { author => 'lisa', title => 'THIS BOOK FIRST' },
                   { author => 'homer', title => 'donuts' },
                   { author => 'bart', title => 'coolness' }
                  );
#this begs for a new structure.
#lets use a hash.
my %authors_books;

#turn your AoH's into a HoA's
#see perldsc for reference
foreach (@things_to_sort){
    push @{$authors_books{$_->{author}}}, $_->{title};
}

#sort the books for each author
foreach my $author (keys %authors_books){
    @{$authors_books{$author}} = sort{
            $a  eq  "THIS BOOK FIRST" && -1
             or  $b  eq  "THIS BOOK FIRST" &&  1 
             or  $a cmp $b
    }@{$authors_books{$author}};
}

#figure out who to display first.
my @display_keys = sort{
        (grep /THIS BOOK FIRST/, @{$authors_books{$a}}) && -1
        or (grep /THIS BOOK FIRST/, @{$authors_books{$b}}) && 1
        or $a cmp $b
    } keys %authors_books;

#display the information.
foreach my $display_key (@display_keys){
    print "$display_key books:\n";
    foreach (@{$authors_books{$display_key}}){
        print "\t$_\n";
    }
}
exit;
[download]

lisa books:
    THIS BOOK FIRST
    postmodernism
bart books:
    coolness
    skateboarding
homer books:
    donuts
marge books:
    hairstyles
[download]