I had no clue what a pseudohash was... until I started searching for "pseudo-hash" instead of "pseudohash". Apparently, you can use an array as a hash. Here's a a snippet from perlref on the subject:

Beginning with release 5.005 of Perl you can use an array reference in some contexts that would normally require a hash reference. This allows you to access array elements using symbolic names, as if they were fields in a structure.

For this to work, the array must contain extra information. The first element of the array has to be a hash reference that maps field names to array indices. Here is an example:

   $struct = [{foo => 1, bar => 2}, "FOO", "BAR"];


   $struct->{foo};  # same as $struct->[1], i.e. "FOO"
   $struct->{bar};  # same as $struct->[2], i.e. "BAR"

   keys %$struct;   # will return ("foo", "bar") in some order
   values %$struct; # will return ("FOO", "BAR") in same some order

   while (my($k,$v) = each %$struct) {
       print "$k => $v\n";
   }
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- Zoogie