#!/usr/bin/perl

use strict;
use warnings;

sub TIESCALAR {
    my $class = shift;
    bless [-1 => [@_]] => $class;
}

sub STORE {die}
sub FETCH {
    ${$_ [0]} [1] [${$_ [0]} [0] ++ % @{${$_ [0]} [1]}];
}

tie $" => main => ":", "-";

my @a = qw /0 1 0 1 0 1 0 1 0 1 0 1/;

print "@a\n";

__END__
0:1-0:1-0:1-0:1-0:1-0:1