Hello Yitzchak, Friday, February 9, 2007, 3:23:53 PM, you wrote:
I would like to use FFI for the first time. Can someone give me a really, really simple complete example?
nothing can be easier main = print (c_mysin 1.0) foreign import ccall "mysin.h mysin" c_mysin :: Double -> Double mysin.c: double mysin(double x) { return sin(x); } mysin.h: double mysin(double x); compilation: ghc -c mysin.c ghc main.hs mysin.o if you need to call imperative function (wjich returns different values for different calls with the same parameters) - just add IO to return type: foreign import ccall "myrnd.h rnd" c_rnd :: Double -> IO Double in C, function defined in the same way as in previous example look also at "Tackling the awkward squad: monadic input/output, concurrency, exceptions, and foreign-language calls in Haskell" http://research.microsoft.com/Users/simonpj/papers/marktoberdorf/marktoberdo... -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com