[Haskell-cafe] FFI and struct arguments

[kyra]

Felipe Lessa wrote:
> Hi,
>
> I tried googling and searching the haskellwiki about this but wasn't
> lucky enough. My question is: is there a way to send struct arguments
> to C functions via the FFI or do I need to create a C wrapper? I guess
> there isn't, and while I can live without it, I'd like to leave no
> doubt.
>   
Sometimes there is such a way. See below.
> Details:
>
> I have something like
>
> ====================
> typedef struct vect {
>     float x,y;
> } vect;
>
> void func(vect v);
>   
For most architectures stack layout of

void func(vect v);

and

void func(float x, float y);

is exactly the same, so for FFI purposes this 'func' can be declared as 
something like:

foreign import ccall unsafe :: Float -> Float -> IO ()


Cheers,
Kyra