Works great here... Using ghci: Prelude> :m + Random Prelude Random> let rand :: (Num a,Random a) => IO a; rand = newStdGen

...

= return . fst . randomR (0,1) Prelude Random> rand :: IO Int 1 Prelude Random> rand :: IO Int 1 Prelude Random> rand :: IO Int 1 Prelude Random> rand :: IO Int 1 Prelude Random> rand :: IO Int 0 Prelude Random> rand :: IO Double 0.6897753065428174 Prelude Random> rand :: IO Float 0.6159074 Prelude Random>

El vie, 23-04-2010 a las 15:33 +0200, Giorgio Stefanoni escribió:

Hi guys,

I'm working with Haskell for a little project at the university and I'm stuck with a problem.

I'm trying to generate a random number in the interval [0.0,1.0]. It is straightforward for me to implement the function on ints:

rand :: IO Int rand = do r <- newStdGen let (x1, r2) = randomR (0,1) r

print x1 return x1

However, if I try to generate a Float instead, I always get an Arithmetic Overflow error that I can not understand.

Code: rand :: IO Float rand = do r <- newStdGen let (x1, r2) = randomR (0.0::Float,1.0::Float) r

print x1 return x1

Do you have any clue why this happens?

Thanks in advance,

-- Giorgio _______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners