{
hunk ./hback.hs 14
+import Debug.Trace (trace)
hunk ./hback.hs 68
+logFileName = "user_scores.db"
hunk ./hback.hs 116
-gameScore v' a' = num / den
+gameScore v' a' = trace (show num ++ " / " ++ show den) $ num / den
hunk ./hback.hs 183
-  visuals <- genStim imgList [] level (level + blockSize)
-  audios <- genStim sndList [] level (level + blockSize)
+  visuals <- genStim level (level + blockSize) imgList []
+  audios <- genStim level (level + blockSize) sndList []
+  trace (show visuals ++ "\n" ++ show audios) return ()
hunk ./hback.hs 192
-    where
-      genStim :: Ord a => [a] -> [a] -> Int -> Int -> IO ([(a, Maybe Bool)])
-      genStim lst hist n cnt
-          | cnt < 1   = return []
-          | otherwise = do
-        c <- if (length hist < n)
-               then (randomElem lst Nothing)
-               else (randomElem lst (Just (head hist)))
-        lst' <- genStim lst (hist ++ [fst c]) n (cnt - 1)
-        return $ c : lst'
+
+-- |genStim level n elementsToChooseFrom accumulator
+--  makes list n-elements long where for each elem:
+--  50% chance it returns same elem as (l items ago); else returns random elem from elems (equal probabilities)
+genStim :: Ord a => Int -> Int -> [a] -> [(a, Maybe Bool)] -> IO ([(a, Maybe Bool)])
+genStim l n elems acc
+    | n < 1 = return $ reverse acc
+    | otherwise = do
+          r <- getStdRandom (randomR (0.0, 1.0)) :: IO Double
+          let mElem = fmap fst $ maybeNth l acc
+          let elems' = case mElem of
+                         Just e -> remove e elems
+                         Nothing -> elems
+          i <- getStdRandom (randomR (0, dec (length elems')))
+          let acc' = chooseWithThreshold 0.5 r elems' i mElem
+          genStim l (dec n) elems (acc' : acc)
+
+chooseWithThreshold :: Double -> Double -> [a] -> Int -> Maybe a -> (a, Maybe Bool)
+chooseWithThreshold _ _ [] index Nothing = error "chooseWithThreshold needs at minimum non-empty list or Just element"
+chooseWithThreshold _ _ [] index (Just x) = (x, Nothing)
+chooseWithThreshold _ _ xs index Nothing = (xs !! index, Nothing)
+chooseWithThreshold t v xs index (Just x)
+    | t <= v = (x, Just True)
+    | otherwise = (xs !! index, Just False)
hunk ./hback.hs 270
-            renderImage (guiDrawArea gui) $ renderRect vZ
-            playSound aZ
-            toggleButtonSetActive (guiVButton gui) False
hunk ./hback.hs 271
+            toggleButtonSetActive (guiVButton gui) False
+            playSound aZ
+            renderImage (guiDrawArea gui) $ renderRect vZ
hunk ./hback.hs 282
-                                        return ((score vB' b1), (score aB' b2))
+                                        return $ trace (show ((score vB' b1), (score aB' b2)))
+                                                       ((score vB' b1), (score aB' b2))
hunk ./hback.hs 398
-           bracket (openFile "user_score_history.db" AppendMode) hClose
+           bracket (openFile logFileName AppendMode) hClose
hunk ./hback.hs 407
-           bracket (openFile "user_score_history.db" AppendMode) hClose
+           bracket (openFile logFileName AppendMode) hClose
hunk ./hback.hs 412
+remove :: Ord a => a -> [a] -> [a]
+remove a = filter (/= a)
+
hunk ./hback.hs 416
-inc = (1+)
+inc = (+1)
+
+dec :: Int -> Int
+dec n = n - 1
+             [_$_]
+maybeNth :: Int -> [a] -> Maybe a
+maybeNth n lst
+    | n < 1 = error "maybeNth: n < 1 not allowed"
+    | otherwise = let l = drop (dec n) lst
+                  in if (null l)
+                        then Nothing
+                        else (Just (head l))
+               [_$_]
+
hunk ./hback.hs 431
--- |randomElem lst c : 50% chance it returns c; else return random elem from lst (equal probabilities)
-randomElem :: Ord a => [a] -> Maybe a -> IO (a, Maybe Bool)
-randomElem lst c' = do
-    case c' of
-      Nothing -> aux lst Nothing
-      Just c  ->  do
-              x <- getStdRandom (randomR (0.0, 1.0)) :: IO Double
-              case (x <= 0.5) of
-                True  -> return (c, Just True)
-                False -> aux (filter (c /=) lst) $ Just False
-    where
-      aux [] _ = error "randomElem: List should not be empty"
-      aux l v = do
-        y <- getStdRandom (randomR (1, length l))
-        return $ (l !! (y - 1), v)
}