use List::Util qw(reduce);
sub compose {
    reduce { sub { $b->($a->(@_)) } } @_;
}

##</code><code>##

sub compose {
    my $c = shift;
    foreach my $s (@_) {
        my $o = $c;
        $c = sub { $s->($o->(@_)) }
    }
    $c
}