$ cat t.pl 
use strict;
use warnings;
use feature qw(say);

use Data::Dumper;

say -  FOO;
say - - BAR;
say - + BLUBBER;

my %hash = (
  - - HHH, 'value',
);
print Dumper(\%hash);

$ perl t.pl 
-FOO
+BAR
-BLUBBER
$VAR1 = {
          '+HHH' => 'value'
        };