I have no experience with the FFI, but conceptually that sounds like a Traversable, not necessarily a Monad. I'd start small, with the simplest superclass, Functor -- so, implement fmap, then move on from there. On Jun 19, 2016 6:48 AM, "nek0" wrote:

Hello fellow haskellers,

I am currently working on Haskell bindings to the GEGL [0] library. Since it's my first time working with the FFI and the whole idea of binding a library into Haskell, I have now run into a problem I can't resolve myself. The GEGL headers expose a function "gegl_buffer_iterator_new" which returns an iterator over a selected area in a buffer. This iterator contains a float pointer with pixel data. My problem is to make the iterator and the data it contains accessible to Haskell and to iterate over it. Can someone of you please help me with this problem? One of my initial thoughts was to wrap it into a monad, but I am totally inexperienced with that. My project can be found on my Github profile [1].

Many thanks in advance,

nek0

links:

[0]: http://www.gegl.org/ [1]: https://github.com/nek0/gegl

_______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.