Re: [Demexp-dev] CDuce binding in Makefile.

[Serge Leblanc]

On Sun, 2004-10-10 at 19:27, David MENTRE wrote: 
> Serge,
>
> Serge Leblanc <address@hidden> writes:
>
> > CDuce was precisely built to handle XML import and export with safety
> > and efficiency since OCaml, look at :
> > http://www.cduce.org/manual_interfacewithocaml.html
> >
> > "Use CDuce as an XML layer (input/output/transformation) for OCaml
> > projects;"
> >
> > The code which CDuce produces can be directly linked with OCaml. 
>
> Ok, I think I'm starting to understand. So we could use CDuce to
> generate a OCaml code that would allow to read/write the XML specific to
> OCaml. Right?

Yes, that's right.

> If true, I have several remarks:
>
>  1. there is no need to include CDuce into demexp source. We could just
>     add it as an external requirements, like ocaml RPC package for
>     example.

That will be well the case. CDuce is also a compiler which from a source .cd file to build a .cmo or .cmx files.

>  2. could you show us (on this list) a simple example of ocaml code
>     produced by CDuce and how we would use it in demexp? No need to
>     start from a real DTD, you could use a dummy example able to parse
>     following xml:
>
> <?xml version="1.0" ?>
>
> <demexp_base version="1.0">
>
>   <participant_base>
>     <participant kind="individual"> <!-- or "delegate" -->
>       <login>root</login>
>       <password>md5pass</password>
>       <group>admin</group>
>       <group>demexp</group>
>     </participant>
>
>   </participant_base>
>
> </demexp_base>
(* demexp.mli *)
val load_demexp: string -> Cduce_lib.Value.t


(* demexp.cd *)
let load_demexp (f : Latin1) : Any = load_xml f ;;


(* demexp_program.ml *)
let t = Demexp.load_demexp "demexp_base.xml" in
  Cduce_lib.Value.dump_xml Format.std_formatter t ;;


ocamlfind ocamlopt -c demexp.mli -I $(ocamlfind query cduce)
cduce --compile demexp.cd -I $(ocamlfind query cduce)
ocamlfind ocamlopt -c -package cduce -pp "cdo2ml -static" -impl demexp.cdo
ocamlfind ocamlopt -o demexp -package cduce -linkpkg  demexp.cmx demexp_program.ml -I ./

This example isn't significant and doesn't profit from CDuce type-safe paradigm.
Here an better example with a type control and a filter optimized by CDuce.

(* demexp.mli *)
val load_demexp: string -> string list

(* demexp.cd *)
let load_demexp (f : Latin1) : [ String* ] =
    let  d = load_xml "demexp_base.xml" in
        map [d]/<participant_base>_/<participant kind="individual">_/<login>String  with
            <login>s -> s
  ;;

(* demexp_program.ml *)
let t = Demexp.load_demexp "demexp_base.xml" in
  Cduce_lib.Value.dump_xml Format.std_formatter t ;;

(* demexp_program.ml *)
let t = Demexp.load_demexp "demexp_base.xml" in
  List.map (Format.printf "@[%s@ address@hidden" "individual:") t ;;

[Here I express myself in French so that my thinking is well understood.]

Ces filtres utilisent les optimisations réalisées et inventées par l'équipe Cduce. Cela est important car toutes les autres méthodes reposant sur un fichier à plat (like: minimal XML from lablgtk2) ne supporteront, pas à terme, la charge des 5 milliards d'utilisateurs. Vous obligeant à implémenter des techniques de base de données qui sont déjà présentes dans CDuce.

>  3. looking at http://www.cduce.org/manual_interfacewithocaml.html#link
>     it says that CDuce compile code to bytecode. Demexp is currently
>     using native code so I would like to be sure that native code can be
>     used.

In the same paragraph documentation says :
"Everything works mutatis mutandis with the native OCaml compiler ocamlopt."

> Yours,
> d.

--
pub  1024D/73791C2B 2002-09-30 Serge Leblanc <address@hidden>
 Primary key fingerprint: 8E0C 0D6D E026 A278 9278  BF4F 1A93 D552 7379 1C2B

signature.asc
Description: This is a digitally signed message part