Someone asked on Perlmonks if a hash could do fuzzy matches on keys - this
is the result.

If there's no exact match on the key that you pass to the hash, then the
key is treated as a regex and the first matching key is returned. You can
force it to leap straight into the regex checking by passing a qr'ed regex
into the hash like this:

  my $val = $h{qr/key/};

exists and delete also do regex matching. In the case of delete all values
matching your regex key will be deleted from the hash.