Allegro CLs yacc?

Hi!

I am working on a project which involves parsing grammars. I have been
looking around for something that works for me, or at least for some
ideas before I write my own version. Any hints on this would be
appreciated.

The reason I am posting this, however, is that I was intrigued when I
was using the new regular expression API and saw:

> cl-user(1): *modules*
> ("efft-emacs-mule-base" "ef-emacs-mule" "efft-latin1-base" "efft-void"
>  "efft-utf8-base" "efft-euc-base" "ef-euc" "euc" "acldns" "composer" ...)
> cl-user(2): 
> ; Fast loading /home/tcmd/lib/acl62/code/regexp2.fasl
> ;;; Installing regexp2 patch, version 0
> ; yacc constructing #<grammar-class regexp> ...
> ; Finis
> cl-user(2): *modules*
> ("regexp2" "yacc-runtime" "yacc-compile" "yacc" "efft-emacs-mule-base"
>  "ef-emacs-mule" "efft-latin1-base" "efft-void" "efft-utf8-base"
>  "efft-euc-base" ...)

I haven't been able to find any reference to yacc in Allegros
documentation, nor have I found anything relevant on the Internet.

I was wondering I if this is something that is intended to be eventually
documented and made available, maybe in Allegro CL 7.0; if this is a
specific version only useful for the regexp2 module; if there is
anything else I am overlooking.

Any comments or ideas related to this subject would be most welcome!

Thank you for your time,
TMD.