sub by_genre { $_[0]->search({ 'me.genre' => $_[1] });
sub since { $_[0]->search({ 'me.released' => { '>=', $_[1] } });

##</code><code>##

my $rs = $schema->resultset('CD');
if ( my $genre = param->{'genre'} ) {
    $rs = $rs->by_genre( $genre );
}
if ( my $since = param->{'since'} ) {
    $rs = $rs->since( $since );
}

##</code><code>##

if ( my $limit = param->{'limit'} ) {
    $rs = $rs->limit_per_artist( $limit );
}