[wg-camlp4] Next steps

[Alain Frisch]

Dear all,

Here are some remaining tasks where some help would be appreciated:

- Starting to port some Camp4 extensions to -ppx with extension_points 
and report on the experience.

(Some examples of tiny ppx filters exist in the experimental/frisch 
directory on the extension_points branch:

http://caml.inria.fr/cgi-bin/viewvc.cgi/ocaml/branches/extension_points/experimental/frisch/Makefile?view=markup
)

- Extend Ast_helper.Convenience with useful functions, as detected while 
rewriting some Camlp4 extensions.

- Update parsing/pprintast.ml to support attributes/extensions.  It is 
the code used when passing "-dsource" to the compiler and it is very 
useful to debug -ppx filters (and other AST-based tools).

- Update Camlp4 (its parsers and its own OCaml AST) to support 
attributes/extensions.


Alain