In case you also want to be able to set dynamically

  DB<44> sub js :lvalue { my $last = pop; my $walk = $js; $walk = $wal
+k->{$_} for @_; $walk->{$last} }

  DB<45> say js(split /-/,"hoig-boig-loig-shmoig")
666

  DB<46> say js(split /-/,"hoig-boig-loig-shmoig") = 42
42

  DB<47> say js(split /-/,"hoig-boig-loig-shmoig")
42

  DB<48> x $js
0  HASH(0x337b528)
   'hoig' => HASH(0x337b768)
      'boig' => HASH(0x337b498)
         'loig' => HASH(0x3379e08)
            'shmoig' => 42
  DB<49>
[download]

see also Data::Diver for more elaborated handling of edge cases