The delimiter is there, you just don't see it. Hence my comments about Data::Dumper's defaults (added shortly after I first posted, so you may have missed them).

$ perl -le '$n=0; $h{"foo"=>$n++}=$n for (0..3); use Data::Dumper; pri
+nt Dumper \%h; $Data::Dumper::Useqq=1; print Dumper \%h'
$VAR1 = {
          'foo1' => 2,
          'foo0' => 1,
          'foo2' => 3,
          'foo3' => 4
        };

$VAR1 = {
          "foo\0341" => 2,
          "foo\0340" => 1,
          "foo\0342" => 3,
          "foo\0343" => 4
        };
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