Из битов в текст

lab3/app/Main.hs

@@ -13,4 +13,7 @@ main = do
     putStrLn $ show (length alphabet)
     let encryptedText = encryptCaesar alphabet caesarShift inputText
     putStrLn $ take 30 encryptedText
-    putStrLn $ concat (take 30 (map show (textToBits encryptedText)))
+    let encryptedTextBits = textToBits encryptedText
+    putStrLn $ concat (take 30 (map show encryptedTextBits))
+    let encryptedTextFromBits = bitsToText encryptedTextBits
+    putStrLn $ take 30 encryptedTextFromBits

lab3/src/Lib.hs

@@ -2,10 +2,11 @@ module Lib
     ( 
         createAlphabetFromText,
         encryptCaesar,
-        textToBits
+        textToBits,
+        bitsToText
     ) where
 
-import Data.Char (ord)
+import Data.Char (ord, chr)
 import Data.Bits (testBit)
 
 createAlphabetFromText :: String -> [Char]
@@ -30,3 +31,10 @@ encryptCaesar alphabet shift text = map caesarChar text
 textToBits :: String -> [Int]
 textToBits = concatMap charToBits
     where charToBits c = [ if testBit (ord c) i then 1 else 0 | i <- [7,6..0] ]    
+
+bitsToText :: [Int] -> String
+bitsToText [] = []
+bitsToText bits = (chr $ bitsToInt (take 8 bits)) : bitsToText (drop 8 bits)
+    where
+        bitsToInt charBits = 
+            sum [bit * (2 ^ index) | (bit, index) <- zip charBits [7 :: Int, 6 .. 0]]