From: Till Varoquaux <till@pps.jussieu.fr>
To: Mathias Kende <mathias.kende@ens.fr>
Cc: Jeffrey Barber <jeff@mathgladiator.com>, caml-list@inria.fr
Subject: Re: [Caml-list] caml_copy_string
Date: Sun, 22 Aug 2010 13:16:44 -0400 [thread overview]
Message-ID: <AANLkTinJai4VJf0=X9_G1eBj1nfioztCe-9pMAr4EAGG@mail.gmail.com> (raw)
In-Reply-To: <1282434367.988.11.camel@mathias-ens>
In byterun/mlvalues.h
#define Bp_val(v) ((char *) (v))
....
#define String_val(x) ((char *) Bp_val(x))
Doesn't look like String_val is doing much copying to me....
Till
On Sat, Aug 21, 2010 at 7:46 PM, Mathias Kende <mathias.kende@ens.fr> wrote:
> Le samedi 21 août 2010 à 18:30 -0500, Jeffrey Barber a écrit :
>> Is there a way to get a string from C to OCaml without the
>> caml_copy_string
>> function, or is there a version that doesn't copy the string?
>
> There is no such function in the Caml FFI. You could write one yourself
> but then the string must have been specially allocated because you need
> to add a one word header to the string and maybe some byte at the end.
> So, if you have to exchange strings between OCaml and C, the easiest way
> is to always allocate them with the caml_alloc_string function. That way
> you can use the pointer returned by String_val in your C code and the
> string remains a valid Caml string (except caml does not use zero as the
> end of string and will stick to its allocated size).
>
> Mathias
>
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next prev parent reply other threads:[~2010-08-22 17:16 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-21 23:30 caml_copy_string Jeffrey Barber
2010-08-21 23:42 ` [Caml-list] caml_copy_string Romain Beauxis
2010-08-21 23:46 ` Mathias Kende
2010-08-22 17:16 ` Till Varoquaux [this message]
2010-08-23 0:42 ` Till Varoquaux
2010-08-23 1:02 ` Jeffrey Barber
2010-08-23 12:09 ` Florent Monnier
2010-08-23 12:59 ` Stéphane Glondu
2010-08-23 13:46 ` Florent Monnier
2010-08-23 20:24 ` Romain Beauxis
2010-08-24 14:21 ` Florent Monnier
2010-08-24 14:52 ` Till Varoquaux
2010-08-24 15:22 ` Anil Madhavapeddy
2010-08-24 15:35 ` Romain Beauxis
2010-08-25 19:16 ` Florent Monnier
2010-08-25 19:33 ` Romain Beauxis
2010-08-25 15:21 ` Goswin von Brederlow
-- strict thread matches above, loose matches on Subject: below --
2005-10-29 0:24 Jonathan Roewen
2005-10-29 0:32 ` Robert Roessler
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