$ perl -Mstrict -Mwarnings -E '
my @a = ( 1 .. 10 );
sub transform (&);
transform { $_ = ( ++ $_ ) % 10 } for @a;
say qq{@a};

sub transform (&) { $_[ 0 ]->( $_ ) }'
2 3 4 5 6 7 8 9 0 1
$