[Haskell-cafe] Haskell DLL crashes Excel

[Kyra]

Andreas Marth wrote:

> type BSTR8 = Ptr Word8
> 
> createBSTR8 :: String -> IO BSTR8
> createBSTR8 s = do
>    let
>      len :: Word32 = fromIntegral (length s)
>      low_l :: Word8 = fromIntegral (len .&. 0xFFFF)
>      low_h :: Word8 = fromIntegral (shiftR len 8 .&. 0xFFFF)
>      high_l :: Word8 = fromIntegral (shiftR len 16 .&. 0xFFFF)
>      high_h :: Word8 = fromIntegral (shiftR len 24 .&. 0xFFFF)
>    arr <- newArray ([low_l,low_h,high_l,high_h] ++ map (fromIntegral .
> fromEnum) s ++ [0])
>    return $! plusPtr arr 4

Use SysAllocString... family. Also, remember they (by convention) have 
to be released from the client side.

Cheers,
Kyra