1-5 to 1-7 generator

gistfile1.hs

import System.Random
import Control.Monad

main = do
        let trials = 100000 
        vals ← collect trials $ zip [1‥7] $ cycle [0] 
        let percents = map (λ(value,amount) → (value,amount / trials)) vals
        print percents

--collect:: Int -> [(Int, Int)] -> IO [(Int, Int)]
collect  0 xs = return xs
collect  n xs = runRandom »= λr → collect (n-1) (addOneToValue r)
        where addOneToValue v = foldl (λys t@(value,amount) → if value ≡ v then (value,amount+1):ys else t:ys) [] xs


runRandom = do
        vals ← mapM (fake (randomRIO (1,5)∷IO Int)) [1‥7]
        let summed = sum vals
        return $ (summed `mod` 7)+1

fake f = \_ -> f