Динамическое извлечение алфавита

lab3/src/Lib.hs

@@ -1,6 +1,12 @@
 module Lib
-    ( someFunc
+    ( 
+        createAlphabetFromText
     ) where
 
-someFunc :: IO ()
-someFunc = putStrLn "someFunc"
+createAlphabetFromText :: String -> [Char]
+createAlphabetFromText [] = []
+createAlphabetFromText (x:xs)
+    | x `elem` alphabet = alphabet
+    | otherwise     = x : alphabet
+  where
+    alphabet = createAlphabetFromText xs