[Haskell-beginners] how to convert an array of foreignPtr a into a list of Ptr a

[鲍凯文]

Hi Frederic,

I tried writing my thoughts on your question in this gist here:
https://gist.github.com/darcykimball/74dd7973b2dbad22b7091135a3b9d472.
There's probably much more to it than what I wrote, but I'm figuring that
stuff out the more I think about it. I'll try to add more when I'm
convinced I get it.

Best,

Kevin

On Tue, Aug 27, 2019 at 5:56 AM <beginners-request at haskell.org> wrote:

> Send Beginners mailing list submissions to
>         beginners at haskell.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
>         http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
> or, via email, send a message with subject or body 'help' to
>         beginners-request at haskell.org
>
> You can reach the person managing the list at
>         beginners-owner at haskell.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Beginners digest..."
>
>
> Today's Topics:
>
>    1.  how to convert an array of foreignPtr a into a   list of Ptr a
>       (PICCA Frederic-Emmanuel)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 27 Aug 2019 07:19:25 +0000
> From: PICCA Frederic-Emmanuel
>         <frederic-emmanuel.picca at synchrotron-soleil.fr>
> To: "The Haskell-Beginners Mailing List - Discussion of primarily
>         beginner-level topics related to Haskell" <beginners at haskell.org>
> Subject: [Haskell-beginners] how to convert an array of foreignPtr a
>         into a  list of Ptr a
> Message-ID:
>         <
> A2A20EC3B8560D408356CAC2FC148E53016CF535AB at SUN-DAG3.synchrotron-soleil.fr>
>
> Content-Type: text/plain; charset="us-ascii"
>
> Hello, I am writing some code whcih use FFI.
>
> one of my C functions has an array of pointer has imput
>
> extern HklBinocularsCube *hkl_binoculars_cube_new(int32_t n_spaces,
>
>  const HklBinocularsSpace **spaces);
>
>
> from Haskell, I have a list of ForeignPtr
> so my question how can I have something like withForeignPtr for an array
> of ForeignPtr
>
> [ForeignPtr a] -> ([Ptr a] -> IO b) -> IO b
>
> Thanks for your help.
>
> Frederic
>
> ------------------------------
>
> Subject: Digest Footer
>
> _______________________________________________
> Beginners mailing list
> Beginners at haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
>
>
> ------------------------------
>
> End of Beginners Digest, Vol 134, Issue 4
> *****************************************
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/beginners/attachments/20190903/7c9ef3b3/attachment.html>