How to build Objects containing itself?

Hi!

So, here's my next question about object orientation in Ada.

In languages like Ruby, C++ or Java, the following construct is
possible (here in Java):

class State {
HashMap<char, Statetransitions = new HashMap<char, State>();
}

Perhaps you're wondering, what this code is meant to be. Some time ago
I programmed a stack-structure simulating a trie as part of a
incremental search-algorithm. The idea was to have a state-object
containing a mapping of characters pointing to state-objects again.
So, the result is a data-structure containing instances of its own
data type again.

As object orientation is a bit different in Ada, the previous code
example would be something like this in Ada:

package State is

type State is tagged
record
Transitions : Transition_Maps.Map;
end record;

package Transition_Maps is new Ada.CMaps
(Key_Type =Character,
Element_Type =State,
"<" ="<",
"=" ="=");
use Transition_Maps;

end State;


As you can see, we have a "What had been there first? The hen or the
egg?"-problem: The State-record requires an instance of
Transition_Maps.Map which is declared after the State-record's
definition. But because Transition_Maps.Map needs a State as
Element_Type changing the order ends in the same problem.

So, has anybody an idea, how to solve this paradox?

Thanks,
Matthias