package Foo;

sub top {
    my($fn) = @_;
    our($d) = ["a", "b"];
    printf "Top before %s [%s]\n", $d, join(",", @$d);
    $fn->($d);
    printf "Top After %s [%s]\n", $d, join(",", @$d);
}


package Bar;

Foo::top(sub {
    our($d) = @_;
    printf "  Before %s [%s]\n", $d, join(",", @$d);
    $d = [];
    printf "  After %s [%s]\n", $d, join(",", @$d);
});

##</code><code>##

C:\Scripts>perl scope.pl
Top before ARRAY(0x183f218) [a,b]
  Before ARRAY(0x183f218) [a,b]
  After ARRAY(0x183f248) []
Top After ARRAY(0x183f218) [a,b]

##</code><code>##

C:\Scripts>perl -v

This is perl, v5.6.1 built for MSWin32-x86-multi-thread
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2001, Larry Wall

Binary build 635 provided by ActiveState Corp. http://www.ActiveState.com
Built 15:34:21 Feb  4 2003