[Haskell-beginners] FFI, Foreign.Marshal.Array, etc.
al at beshenov.ru
Wed Nov 26 17:16:17 EST 2008
On Wednesday 26 November 2008 23:32:58 Alexey Beshenov wrote:
> I'm playing with the FFI.
> Could anyone help me with a practical example?
> I have a function
> int solve_sys (double **a, int n, double b);
> where a is an array of size n*n and b is an array of size n
> (it contains the needed result if solve_sys returns 0).
> How could I wrap it in something like
> solveSys :: [[Double]] -> [Double] -> [Double]
Something like this:
foreign import ccall "linear.h solve_sys" lSolve :: Ptr (Double) ->
Int -> Ptr (Double) -> IO (Int)
solveSys :: [[Double]] -> [Double] -> IO()
solveSys a b = do
aptr <- newArray (concat a)
bptr <- newArray b
sol <- lSolve aptr n bptr
x <- peekArray n bptr
where n = length a
Does the trick, but I wonder is there a way to get a function
Setting Orange, Aftermath 38 YOLD 3174
Alexey Beshenov http://beshenov.ru/
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