extends Ptree/Typing API to the entire mlw file
As you know, the parser doesn't provide ptrees but pmodules. Nevertheless, it would be nice to be able to build the whole mlw file as a Ptree.
This is a proposal for a minimal extension of the Ptree / Typing API in that sense.
In short :
- new type Ptree.mlw_file (which needs new constructors in Ptree.decl for "use import" "use export" "import" "scope" "clone import" "clone export")
- typing.ml/mli : type_mlw_file is now the only function a user needs for the typing procedure (cf examples/use_api/mlw_tree.ml)