Re: [Caml-list] camlp4 3.10 questions

["Nicolas Pouillard" <nicolas.pouillard@gmail.com>]

On 3/30/07, Hendrik Tews <H.Tews@cs.ru.nl> wrote:
> "Nicolas Pouillard" <nicolas.pouillard@gmail.com> writes:
>
>    On 3/29/07, Hendrik Tews <H.Tews@cs.ru.nl> wrote:
>    > "Nicolas Pouillard" <nicolas.pouillard@gmail.com> writes:
>    >
>    >    > 2. There are various maps and folds on asts in Sig.Camlp4Ast. How
>    >    >    can I use them?
>    >
>    >    2/ There is a lot of shortcuts to made the use of them easier when one
>    >    just want to hook up only one thing (expressions for instance).
>    >
>    >    The same example.
>    >
>    >    open Camlp4.PreCast
>    >    let f = Ast.map_expr begin function
>    >        | <:expr< $x$ + 0 >> | <:expr< 0 + $x$ >> -> x
>    >        | e -> e
>    >    end in
>    >    AstFilters.register_str_item f#str_item
>    >
>    > That should be  AstFilters.register_str_item f ?
>
>    Nop, giving the up to date signature of Ast.map_exp:
>
>    value map_expr : (expr -> expr) -> map;
>
> Where does this come from? I only found
>
>   value map_expr : (expr -> expr) -> expr -> expr;

Yes that's the old one.

>    >    > 8. How can I process multiple files with the same camlp4 process?
>
>    You're right only one file (implem or interf).
>    So you can't by command line.
>
> Well, I guessed that. But how about using the API?

I've put an example in camlp4/example/parse_files.ml
I've also improved a little the API by flattening the small modules
Syntax.{Parser,Printer,Warning} into Syntax itself.

The example make a new syntax module (the Caml one), then parse two
files make, then join both ASTs, and then print it.

(*******************************)
open Camlp4.PreCast;;

module CamlGram = MakeGram(Lexer);;

module Caml =
  Camlp4.Printers.OCaml.Make
    (Camlp4OCamlParser.Make
      (Camlp4OCamlRevisedParser.Make
        (Camlp4.OCamlInitSyntax.Make(Ast)(Gram)(Quotation))));;

let parse f =
  let ic = open_in f in
  let strm = Stream.of_channel ic in
  let res = Caml.parse_implem (Loc.mk f) strm in
  close_in ic; res;;

let ghost = Loc.ghost;;

let main () =
  let a = parse "apply_operator_test.ml" in
  let b = parse "global_handler_test.ml" in
  Caml.print_implem
    <:str_item@ghost<
      module Apply_operator_test = struct $a$ end;;
      module Global_handler_test = struct $b$ end >>
;;

try main ()
with e ->
  Format.eprintf "error: %a@." Camlp4.ErrorHandler.print e;
  exit 1;;
(*******************************)

Best regards,

-- 
Nicolas Pouillard