Hi, was experimenting with your code, couldn't solve it but here are my 2 cents.

use strict ;
use warnings ;
use Data::Dumper ;

my @limit = (reverse 1..5) ;
my $limit = { _l => \@limit } ;
bless ( $limit, 'limit' ) ;
sub countdown {
    my $val = shift ;
    my $iter = sub {
        if ( $val-- ) {
            $_[0] = $val ;
            return 1 ;
        }
        return ;
    } ;
    return $iter ;
}
while ( my $iter = $limit->Next( *countdown ) ) {
    while ( $iter->( my $a ) ) {
        print "$a: " ;
    }
    print "\n" ;
}

package limit ;
use strict ;
use warnings ;
use Data::Dumper ;
sub Next {
    my $this = shift ;
    if ( @{$this->{_l}} ) {
        return $_[0]->( shift @{$this->{_l}} ) ;
    }
    return ;
} ;
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