Please, I just can not figure this out:

I have a method in my C dll:

int somemethod(char *param, int length, double array[], int UB1, int UB2, bool isValid);

I would like to use this method in Haskell, so I have defined it like:

{-# OPTIONS_GHC -fglasgow-exts #-}

import Foreign

import Foreign.C

foreign import stdcall unsafe "somemethod" c_somemethod :: Ptr CString

-> Int

-> Ptr (Double)

-> Int

-> Bool

-> IO Int

main = do

let param = ["input"]

let paramLength = length param

realTable = [ 1.0, 2.0, 3.0 ] :: [Double]

ub1 = 0

ub2 = 2

isValid = False

realTablePtr <- newArray realTable

x <- c_somemethod param paramLength realTablePtr ub1 ub2 isValid

free realTablePtr

putStrLn $ "c_somemethod output: " ++ show x

putStrLn "Done"

When I try to compile this I get error regarding the param string. I have no idea how to define it. Additionally to this, is the freeing of realTablePtr correct?

compile error:

Couldn't match expected type `Ptr CString' with actual type `[t0]'

In the first argument of `c_somemethod', namely `param'

Please, how can I ix this?

cheers,