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

[Fabrice Le Fessant <Fabrice.Le_fessant@inria.fr>]

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You might want to split your file in two different files, a loader and the
body:

 peerocaml:~%  cat > script_body.ml
open Sexplib.Std;;
type t = int with sexp;;
 peerocaml:~%  cat > script.ml
#use "topfind";;
#camlp4o;;
#require "sexplib.syntax";;
#use "script_body.ml"
 peerocaml:~%  ocaml script.ml

--Fabrice
INRIA & OCamlPro




On Wed, Jul 2, 2014 at 1:48 PM, Philippe Veber <philippe.veber@gmail.com>
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 | 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
> >:
>
> 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>
>> wrote:
>>
>>> Thanks David!
>>>
>>> The first call fails with a syntax error on "with sexp":
>>>
>>> [pbil:~ 18:58]$cat rien.ml
>>>
>>> let () =
>>>   try Topdirs.dir_directory (Sys.getenv "OCAML_TOPLEVEL_PATH")
>>>   with Not_found -> ()
>>> ;;
>>>
>>> #use "topfind";;
>>> #camlp4o;;
>>> #require " sexplib.syntax";;
>>>
>>> open Sexplib.Std;;
>>>
>>> type t = int with sexp;;
>>>
>>> [pbil:~ 18:58]$ocaml rien.ml
>>> File "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>:
>>>
>>> On Tue, Jul 1, 2014 at 5:38 PM, Philippe Veber <philippe.veber@gmail.com>
>>>> wrote:
>>>> > Reposting this question here, just in case.
>>>> >
>>>> > ---------- Forwarded message ----------
>>>> > From: Philippe Veber <philippe.veber@gmail.com>
>>>> > Date: 2014-06-28 21:32 GMT+02:00
>>>> > Subject: Toplevel and syntax extension.
>>>> > To: 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, the simple call:
>>>> >
>>>> > ocaml script.ml
>>>> >
>>>> > fails while the call:
>>>> >
>>>> > cat 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
>>
>
>


-- 
Fabrice LE FESSANT
Chercheur en Informatique
INRIA Paris Rocquencourt -- OCamlPro
Programming Languages and Distributed Systems

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