Re: [Caml-list] Fwd: Toplevel and syntax extension.

[Ashish Agarwal <agarwal1975@gmail.com>]

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Yet another option is to use ocamlscript. The following works:

$ cat script.ml
#! /usr/bin/env ocamlscript
Ocaml.ocamlflags := ["-thread"];
Ocaml.packs := ["sexplib.syntax"]
--
open Sexplib.Std
type t = int with sexp

$ ./script.ml
(* compiles without error *)




On Wed, Jul 2, 2014 at 10:48 AM, Philippe Veber <philippe.veber@gmail.com>
wrote:

> Thanks Romain, I'll rather use Fabrice's suggestion, which handles
> command-line argument more simply.
>
> Cheers,
>
>  Philippe.
>
>
> 2014-07-02 14:01 GMT+02:00 Romain Bardou <romain.bardou@inria.fr>:
>
> You could write a wrapper which start the ocaml process, sends a string
>> containing something like:
>>
>> module Sys =
>> struct
>>   include Sys
>>   let argv = ... (* fill this *)
>> end
>>
>> to the ocaml process (replace the ... by the arguments given to the
>> wrapper, using the array syntax, and don't forget that the first cell
>> must contain the executable path), and then pass the contents of your
>> script.ml.
>>
>> This does not work if your script uses other modules which themselves
>> use Sys.argv.
>>
>> Cheers,
>>
>> -- Romain Bardou
>>
>> On 02/07/2014 13:48, Philippe Veber wrote:
>> > Thanks Fabrice, this perfectly explains what I observe. Is this behavior
>> > considered the right one? Reading from a pipe is regretfully not an
>> > option for me, as my script has command line arguments. Hence when I
>> type:
>> >
>> > cat script.ml <http://script.ml> | ocaml --foo --bar 1
>> >
>> > the toplevel complains it knows nothing about the arguments foo and bar.
>> > A "--" argument would be useful but it seems not available. If it's so,
>> > I'll file a feature request on Mantis, since without it, there seems to
>> > be no way to give a script to the toplevel that both takes command line
>> > arguments and uses a syntax extension.
>> >
>> > Thanks again!
>> >
>> >
>> >
>> > 2014-07-02 10:08 GMT+02:00 Fabrice Le Fessant
>> > <Fabrice.Le_fessant@inria.fr <mailto:Fabrice.Le_fessant@inria.fr>>:
>> >
>> >     If I remember well, I think "ocaml" has a different behavior
>> >     depending on what it reads from:
>> >     * From a pipe, it parses every sentence and execute each one
>> >     immediatly.
>> >     * From a file, it tries to parse the whole file, and then executes
>> >     everything.
>> >
>> >     In the second case, it means it will only execute the load of the
>> >     syntax extension after parsing the whole file... which will fail,
>> >     since the syntax extension is needed for that.
>> >
>> >     --Fabrice
>> >     INRIA & OCamlPro
>> >
>> >
>> >
>> >     On Tue, Jul 1, 2014 at 7:06 PM, Philippe Veber
>> >     <philippe.veber@gmail.com <mailto:philippe.veber@gmail.com>> wrote:
>> >
>> >         Thanks David!
>> >
>> >         The first call fails with a syntax error on "with sexp":
>> >
>> >         [pbil:~ 18:58]$cat rien.ml <http://rien.ml>
>> >
>> >         let () =
>> >           try Topdirs.dir_directory (Sys.getenv "OCAML_TOPLEVEL_PATH")
>> >           with Not_found -> ()
>> >         ;;
>> >
>> >         #use "topfind";;
>> >         #camlp4o;;
>> >         #require " sexplib.syntax";;
>> >
>> >         open Sexplib.Std;;
>> >
>> >         type t = int with sexp;;
>> >
>> >         [pbil:~ 18:58]$ocaml rien.ml <http://rien.ml>
>> >         File "rien.ml <http://rien.ml>", line 12, characters 13-17:
>> >         Error: Syntax error
>> >
>> >         It seems like the sexp syntax extension is not loaded when the
>> >         script is evaluated. But it's not really clear to me what going
>> >         wrong...
>> >
>> >         Cheers!
>> >         ph.
>> >
>> >
>> >
>> >         2014-07-01 18:51 GMT+02:00 David Sheets <sheets@alum.mit.edu
>> >         <mailto:sheets@alum.mit.edu>>:
>> >
>> >             On Tue, Jul 1, 2014 at 5:38 PM, Philippe Veber
>> >             <philippe.veber@gmail.com <mailto:philippe.veber@gmail.com
>> >>
>> >             wrote:
>> >             > Reposting this question here, just in case.
>> >             >
>> >             > ---------- Forwarded message ----------
>> >             > From: Philippe Veber <philippe.veber@gmail.com
>> >             <mailto:philippe.veber@gmail.com>>
>> >             > Date: 2014-06-28 21:32 GMT+02:00
>> >             > Subject: Toplevel and syntax extension.
>> >             > To: ocaml_beginners@yahoogroups.com
>> >             <mailto:ocaml_beginners@yahoogroups.com>
>> >             >
>> >             >
>> >             > Dear camlers,
>> >             >
>> >             > Consider the following script:
>> >             >
>> >             > #use "topfind";;
>> >             > #camlp4o;;
>> >             > #require "sexplib.syntax";;
>> >             >
>> >             > open Sexplib.Std;;
>> >             >
>> >             > type t = int with sexp;;
>> >             >
>> >             > Saved as script.ml <http://script.ml>, the simple call:
>> >             >
>> >             > ocaml script.ml <http://script.ml>
>> >             >
>> >             > fails while the call:
>> >             >
>> >             > cat script.ml <http://script.ml> | ocaml
>> >             >
>> >             > succeeds. Any idea how I could fix the first call?
>> >
>> >             How does the first call fail? A difference between the two
>> >             is that, in
>> >             the second, the .ocamlinit file is used. If you are using
>> >             opam with
>> >             ocamlfind installed via it, this file will contain your
>> >             Topdirs setup.
>> >             You can try:
>> >
>> >             let () =
>> >               try Topdirs.dir_directory (Sys.getenv
>> "OCAML_TOPLEVEL_PATH")
>> >               with Not_found -> ()
>> >             ;;
>> >
>> >             at the top of your script (after hashbang but before
>> >             directives).
>> >
>> >             Hope this helps,
>> >
>> >             David
>> >
>> >
>> >
>> >
>> >
>> >     --
>> >     Fabrice LE FESSANT
>> >     Chercheur en Informatique
>> >     INRIA Paris Rocquencourt -- OCamlPro
>> >     Programming Languages and Distributed Systems
>> >
>> >
>>
>>
>

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