# Represents
# AA Sections are cool
# AB They are extremely cool
# ABAA That's right, really cool
# ABAB Again, really cool
my $sections = [
                {content => 'Sections are cool' },

                {content => 'They are extremely cool',
                 subsecs => [
                             { content => "That's right, really cool" },
                             { content => "Again, really cool" },
                            ]
                 }
               ];


##</code><code>##

recurse_section( $sections );

sub recurse_section {
    my ($sections, @vaportrail) = @_;

    push @vaportrail, 'AA';
    foreach my $section (@$sections) {
        print @vaportrail, " ", $section->{'content'}, "\n";

        recurse_section($section->{subsecs}, @vaportrail)
            if defined $section->{subsecs};

        $vaportrail[ $#vaportrail ]++
    }
}

##</code><code>##

# Add a supersection above "They are extremely cool"
my $moving_section = $sections->[1];
$sections->[1] = { content => 'And moving sections is easy too!', subsecs => [ $moving_section ] };
recurse_section( $sections );