Thanks Anonymous Monk,

Unfortunately, the output of:
   perl -MO=Deparse,-p test.pl
doesn't tell me much (in this case):

($item = 'Test');
($level = ((($access{$item} // (($item =~ /^([^:]+):/) && $access{"$1:
+*"})) // $access{'*'}) // 999));
print("level='${level}'\n");
test.pl syntax OK
[download]

But thanks for the link to the other things on the debugging page.