Fix warnings

.gitignore

@@ -0,0 +1 @@
+/.stack-work/

app/Main.hs

@@ -1,20 +1,23 @@
-module Main where
+module Main (main) where
 
-import System.IO            (IOMode(ReadMode), Handle, openFile, hGetChar, hGetLine, hIsEOF)
-import Data.Map.Strict      (Map, empty, insertWith)
-import Data.Vector.Unboxed  (Vector(..))
+import           Data.Vector.Unboxed (Vector)
 import qualified Data.Vector.Unboxed as Vec
-import Data.Word            (Word16(..))
+import           Data.Word           (Word16)
+import           System.IO           (Handle, IOMode (ReadMode), hGetChar,
+                                      hGetLine, hIsEOF, openFile)
 
 data Nucleotide = A | C | T | G deriving (Enum, Eq, Ord, Show)
 
 type GWord = [Nucleotide]
 
 codeWord :: GWord -> Word16
-codeWord gWord = fromIntegral (sum [4^i * (fromEnum nuc) | (i, nuc) <- zip [0..] gWord])
+codeWord gWord =
+    fromIntegral $
+    sum [4 ^ i * fromEnum nuc | (i, nuc) <- zip [0 :: Int ..] gWord]
 
-decodeWord :: Word16 -> GWord
-decodeWord word = [toEnum (fromIntegral((div word (4^i)) `mod` 4)) | i <- [0..5]]
+-- decodeWord :: Word16 -> GWord
+-- decodeWord word =
+--     [toEnum . fromIntegral $ word `div` 4 ^ i `mod` 4 | i <- [0 .. 5 :: Int]]
 
 readNucleotide :: Char -> Maybe Nucleotide
 readNucleotide symbol =
@@ -35,10 +38,9 @@ readWord nuclCount file = do
             case readNucleotide symbol of
                 Just nucleotide -> do
                     gWord <- readWord (nuclCount - 1) file
-                    pure ([nucleotide] ++ gWord)
-                Nothing -> do
-                    gWord <- readWord nuclCount file
-                    pure gWord
+                    pure $ nucleotide : gWord
+                Nothing ->
+                    readWord nuclCount file
     else
         pure []
 
@@ -47,8 +49,7 @@ countWords filepath = do
     genomeHandle <- openFile filepath ReadMode
     _ <- hGetLine genomeHandle
     firstWord <- readWord 6 genomeHandle
-    gWords <- countWord firstWord (Vec.replicate 4096 0) genomeHandle
-    pure gWords
+    countWord firstWord (Vec.replicate 4096 0) genomeHandle
 
 countWord :: GWord -> Vector Word16 -> Handle -> IO (Vector Word16)
 countWord gWord vector handle = do
@@ -57,7 +58,7 @@ countWord gWord vector handle = do
         symbol <- hGetChar handle
         case readNucleotide symbol of
             Just nucleotide -> do
-                let newWord = (tail gWord) ++ [nucleotide]
+                let newWord = tail gWord ++ [nucleotide]
                 countWord
                     newWord
                     (Vec.accum (+) vector [(fromIntegral $ codeWord gWord, 1)])
@@ -69,5 +70,5 @@ countWord gWord vector handle = do
 
 main :: IO ()
 main = do
-    words <- countWords "genome.fna"
-    print words
+    wordsCount <- countWords "genome.fna"
+    print wordsCount