diff --git a/src/GEval/LineByLine.hs b/src/GEval/LineByLine.hs
index d44e9d4..b2ee4b3 100644
--- a/src/GEval/LineByLine.hs
+++ b/src/GEval/LineByLine.hs
@@ -9,7 +9,9 @@
 
 module GEval.LineByLine
        (runLineByLine,
-        runDiff
+        runLineByLineGeneralized,
+        runDiff,
+        runDiffGeneralized
        ) where
 
 import GEval.Core
@@ -31,11 +33,8 @@ data LineRecord = LineRecord Text Text Text Word32 MetricValue
                   deriving (Eq, Show)
 
 runLineByLine :: GEvalSpecification -> IO ()
-runLineByLine spec = do
-  (inputFilePath, expectedFilePath, outFilePath) <- checkAndGetFiles spec
-  gevalLineByLineCore metric inputFilePath expectedFilePath outFilePath consum
-   where metric = gesMetric spec
-         consum :: ConduitT LineRecord Void (ResourceT IO) ()
+runLineByLine spec = runLineByLineGeneralized spec consum
+   where consum :: ConduitT LineRecord Void (ResourceT IO) ()
          consum = (CL.map (encodeUtf8 . formatOutput) .| CC.unlinesAscii .| CC.stdout)
          formatOutput (LineRecord inp exp out _ score) = Data.Text.intercalate "\t" [
            formatScore score,
@@ -45,18 +44,15 @@ runLineByLine spec = do
          formatScore :: MetricValue -> Text
          formatScore = Data.Text.pack . printf "%f"
 
-runDiff :: FilePath -> GEvalSpecification -> IO ()
-runDiff otherOut spec = do
-  let otherOutFilePath = getOutFile spec otherOut
+runLineByLineGeneralized :: GEvalSpecification -> ConduitT LineRecord Void (ResourceT IO) a -> IO a
+runLineByLineGeneralized spec consum = do
   (inputFilePath, expectedFilePath, outFilePath) <- checkAndGetFiles spec
-  let sourceA = gevalLineByLineSource metric inputFilePath expectedFilePath outFilePath
-  let sourceB = gevalLineByLineSource metric inputFilePath expectedFilePath otherOutFilePath
-  runResourceT $ runConduit $
-     ((getZipSource $ (,)
-       <$> ZipSource sourceA
-       <*> ZipSource sourceB) .| consum)
+  gevalLineByLineCore metric inputFilePath expectedFilePath outFilePath consum
   where metric = gesMetric spec
-        consum :: ConduitT (LineRecord, LineRecord) Void (ResourceT IO) ()
+
+runDiff :: FilePath -> GEvalSpecification -> IO ()
+runDiff otherOut spec = runDiffGeneralized otherOut spec consum
+  where consum :: ConduitT (LineRecord, LineRecord) Void (ResourceT IO) ()
         consum = (CL.filter shouldBeShown .| CL.map (encodeUtf8 . formatOutput) .| CC.unlinesAscii .| CC.stdout)
         shouldBeShown (LineRecord _ _ outA _ scoreA, LineRecord _ _ outB _ scoreB) =
           outA /= outB && scoreA /= scoreB
@@ -69,10 +65,22 @@ runDiff otherOut spec = do
         formatScoreDiff :: Double -> Text
         formatScoreDiff = Data.Text.pack . printf "%f"
 
+runDiffGeneralized :: FilePath -> GEvalSpecification -> ConduitT (LineRecord, LineRecord) Void (ResourceT IO) a -> IO a
+runDiffGeneralized otherOut spec consum = do
+  let otherOutFilePath = getOutFile spec otherOut
+  (inputFilePath, expectedFilePath, outFilePath) <- checkAndGetFiles spec
+  let sourceA = gevalLineByLineSource metric inputFilePath expectedFilePath outFilePath
+  let sourceB = gevalLineByLineSource metric inputFilePath expectedFilePath otherOutFilePath
+  runResourceT $ runConduit $
+     ((getZipSource $ (,)
+       <$> ZipSource sourceA
+       <*> ZipSource sourceB) .| consum)
+  where metric = gesMetric spec
+
 escapeTabs :: Text -> Text
 escapeTabs = Data.Text.replace "\t" "<tab>"
 
-gevalLineByLineCore :: Metric -> FilePath -> FilePath -> FilePath -> ConduitT LineRecord Void (ResourceT IO) () -> IO ()
+gevalLineByLineCore :: Metric -> FilePath -> FilePath -> FilePath -> ConduitT LineRecord Void (ResourceT IO) a -> IO a
 gevalLineByLineCore metric inputFilePath expectedFilePath outFilePath consum =
   runResourceT $ runConduit $
      ((gevalLineByLineSource metric inputFilePath expectedFilePath outFilePath) .| consum)