various improvements, corrected logic errors

phase2.hs

@@ -8,12 +8,21 @@ import Control.Monad(when)
 main :: IO()
 main = do
     args <- getArgs
-    when (2 /= length args) (error "Usage: phase2 <file.csv> <threshold>")
-    let filename = head args
+    when (3 /= length args) (error "Usage: phase2 <table.csv> <frequents.csv> <threshold>")
     let threshold = read $ last args
-    file <- readFile filename
-    case parseCSV file of
-        Left _ -> error "Could not parse out.csv"
-        Right val -> do
-            let table = map (ItemSet. Set.fromList .map Item) val
-            print $ extractRules threshold table
+    tableFile <- readFile $ head args
+    freqFile <- readFile $ args !! 1
+    case parseCSV tableFile of
+        Left _ -> error "Could not parse table"
+        Right tableFileContent ->
+            case parseCSV freqFile of
+                Left _ -> error "Could not parse frequent patterns"
+                Right freqFileContent -> do
+                    putStrLn output
+                    when (length args > 2) $
+                        writeFile (args !! 2) $ output
+                    where
+                        freqPats = map (ItemSet. Set.fromList .map Item) (map tail freqFileContent)
+                        table = map (ItemSet. Set.fromList .map Item) tableFileContent
+                        rules = extractRules threshold table freqPats
+                        output = init $ foldr (\x old -> old++x++"\n") "" $ map show rules