semantic actions

[Bob Rossi]

Hi,

I'm using bison along with it's semantic actions. In particular, I'm
using the $$, $1, $2 constructs in order to help me build a parse tree.

In the past, I've place the top level AST type as a global object, and
the top level rule would assign it's $$ to that global variable.

However, I'm wondering if it's possible, after the parse is done, to ask
bison to give you back the top level's rule $$ variable. That way, I
don't have to keep around an extra global variable. 

Is this question clear enough to be answerable? :)

Thanks,
Bob Rossi