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Date: Mon, 17 Jun 2002 11:35:14 +0200
From: =?iso-8859-1?Q?J=E9r=F4me_Marant?= <jerome.marant@fr.thalesgroup.com>
To: caml-list@inria.fr
Subject: [Caml-list] C <-> OCaml questions
Message-ID: <20020617113514.A30103@fr.thalesgroup.com>
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Hello,

  I'm currently writing OCaml bindings for some C libraries and
  I would like to get some details about how to convert C pointers
  to OCaml types.

  1/
  Let's assume we have the following C function:

    Bar * Foo(char *S);

  In OCaml, I would like to convert the (Bar *) type to

   type bar

  Question: how do I perform the conversion? Should I allocate
  a bloc of size sizeof(Bar *), assign the pointer value to it
  and return it to OCaml?
  How can I make it portable, i.e. independant on the size of
  pointers ? (32 or 64 bits).

  2/
   Let's assume we have the same C function:

   Bar * Foo(char *S);

   The OCaml matching function should be:

   val foo: string -> bar

   Now assume that NULL is a significant value for S.
   How can I tell OCaml to pass NULL to the C function?
   Should I create a specific version of foo with no
   argument but which passed NULL in the C interface?

  Thanks in advance.

  Regards,=20

--=20
J=E9r=F4me Marant
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