small updates, use BL and withFile

examples/recurrent.hs

@@ -9,7 +9,7 @@ module Main where
   import System.IO
   import Data.Default.Class
   import Data.List (genericLength)
-  import qualified Data.ByteString.Lazy.Char8 as BSL
+  import qualified Data.ByteString.Lazy.Char8 as BL
 
   main = do
     texts <- lines <$> readFile "examples/reddit.csv"
@@ -21,9 +21,6 @@ module Main where
     let x0 = reverse . drop 1 . reverse $ indexes !! 0
         y0 = drop 1 $ indexes !! 0
 
-    print $ x0
-    print $ y0
-
     let xs = map (reverse . drop 1 . reverse) indexes
         ys = map (drop 1) indexes
 
@@ -32,34 +29,32 @@ module Main where
 
     let newr = sgd r (take 1 xs) (take 1 vys) 0.005 1
 
-    saveRecurrent "recurrent.trained" (show newr) 512
-    --writeFile "recurrent.trained" (show newr)
-
     let newpredicted = predict newr x0
     print $ y0
     print $ newpredicted
 
     print $ loss (tov y0) (tov newpredicted)
 
-    {-let (dU, dV, dW) = backprop r x0 (fromList $ map fromIntegral y0)-}
-    {-print $ seq u "u"-}
-    {-print $ seq v "v"-}
-    {-print $ seq w "w"-}
-
-    --print $ dW
     print "done"
 
+    saveRecurrent "recurrent.trained" (show newr) 512
+
   saveRecurrent :: FilePath -> String -> Int -> IO ()
   saveRecurrent path str chunkSize = do
-    handle <- openFile path AppendMode
-    hSetBuffering handle NoBuffering
-    loop handle str
-    hClose handle
+    let b = BL.pack str
+    withFile path AppendMode (process b)
     where
-      loop _ [] = return ()
-      loop handle s = do
-        hPutStr handle $ take chunkSize s
-        hFlush handle
-        putStr $ take chunkSize s
-        loop handle $ drop chunkSize s
+      process :: BL.ByteString -> Handle -> IO ()
+      process b handle = do
+        hSetBuffering handle NoBuffering
+        loop handle b
+
+      loop :: Handle -> BL.ByteString -> IO ()
+      loop handle s 
+        | s == BL.empty = return ()
+        | otherwise = do
+          let (current, next) = BL.splitAt (fromIntegral chunkSize) s
+          BL.hPutStr handle current
+          hFlush handle
+          loop handle next