reworked modules to allow for multiple executables

DataModel.hs

@@ -0,0 +1,39 @@
+module DataModel where
+import Data.Set (Set)
+import qualified Data.Set as Set
+
+type Count = Int
+
+type Frequency = Double
+type Confidence = Double
+
+class Freq a where
+	frequency :: [ItemSet] -> a -> Frequency
+
+data Item = Item String deriving (Eq, Ord)
+instance Show Item where
+	show (Item s) = s --"Item " ++ s
+
+data ItemSet = ItemSet (Set Item) deriving (Eq, Ord)
+
+instance Show ItemSet where
+	show (ItemSet x) = foldr ((\y old -> y ++ " " ++ old).show) "" (Set.toList x)
+
+instance Freq ItemSet where
+	frequency table (ItemSet set) = setCount / fromIntegral (length table) where
+		setCount = fromIntegral $ count table (ItemSet set)
+
+count :: [ItemSet] -> ItemSet -> Count
+count table (ItemSet set) = length (filter (\(ItemSet row) -> set `Set.isSubsetOf` row) table)
+
+data Rule = Rule ItemSet ItemSet deriving (Eq)
+
+instance Show Rule where
+	show (Rule a b) = show a ++ "-> " ++ show b
+
+instance Freq Rule where
+	frequency table (Rule (ItemSet set1) (ItemSet set2)) = frequency table $ ItemSet (set1 `Set.union` set2)
+
+confidence :: [ItemSet] -> Rule -> Confidence
+confidence table (Rule x y) = frequency table (Rule x y) / frequency table x
+