[C2hs] Marshal Haskell list into monolithic arrays

[Duncan Coutts]

On Thu, 2006-08-17 at 14:20 +0000, zhu Jun wrote:
> Hi all,
> 
> There is a 'newArray' operation in MarshallArray to marshal Haskell list, 
> with the definination of 'newArray :: Storable a => [a] -> IO (Ptr a)'. 
> However, when I pass the 'Ptr a' to a C function, only the the first 
> element of the list is available in C.
> Could anyone give some hints?
> 
> The C function looks like:
> ////////////////////
> void lowPassFilter(float *fs[10], float *sum)
> {
>  // Only *fs[0] is available here, why?
> }
> //////////////
> with the import call in Haskell like this:
> foreign import ccall safe "lowPassFilter" lowPassFilter :: Ptr (CFloat) -> 
> Ptr (CFloat) -> IO (())

How are you calling this? Show us the code where you use lowPassFilter
and newArray.

> Should I use ' lowPassFilter :: Ptr ([CFloat]) -> Ptr (CFloat) -> IO (())', 
> and define 'float fs[10]' to be Storable in Haskell?

No.

Duncan