ちょっと訂正

my @events = ();
$events[5] = [ sub {return 0} => sub {print 5} ];
$events[6] = [ sub {return 1} => sub {print 6} ];

foreach(@events) {
　　my $event = $_ // [ sub {} => undef] ;
　　my ($cond, $process) = @$event;

　　$process->() if $cond->();
}