perl -MO=Deparse,-P -e 'my ($x, @y) = (1,2,,,,,); print $#y'

##</code><code>##

$ perl -MO=Deparse -e 'my ($x, @y) = (1,2,,,,,); print $#y'
my($x, @y) = (1, 2);
print $#y;
-e syntax OK

##</code><code>##

$ perl -MO=Deparse,-p -e 'my ($x, @y) = (1,2,,,,,); print $#y'
(my($x, @y) = (1, 2));
print($#y);
-e syntax OK