Hello Brian, Tuesday, March 7, 2006, 7:35:27 PM, you wrote: BH> foreign import ccall duma_init :: Int -> IO Int int duma_init(int); BH> I've tried looking at the wiki but that only seems to give specific BH> examples. I'm trying to find what the mapping is between Haskell function BH> signatures and C signatures is in general. Any ideas? see official FFI documentation - http://www.cse.unsw.edu.au/~chak/haskell/ffi/ffi.pdf and excellent paper "Tackling the awkward squad: monadic input/output, concurrency, exceptions, and foreign-language calls in Haskell" (http://research.microsoft.com/Users/simonpj/papers/marktoberdorf/marktoberdo...) BH> Also, I really wanted to be able to use () -> IO () but () doesn't seem to BH> be allowed in FFI... void f(void); foreign import ccall f :: IO () BH> A third point is, how would I pass an arbitrary monad instead of just using BH> IO? if you are sure what you do, you can even declare C function as pure: foreign import ccall duma_init :: Int -> Int -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com