add day3

day3/app/Main.hs

@@ -0,0 +1,21 @@
+module Main where
+
+import Data.Char (isDigit)
+import qualified Data.HashSet as HashSet
+import Data.List.Split (splitOn)
+
+getSeparators :: String -> [Char]
+getSeparators = filter checkSeparator
+
+checkSeparator :: Char -> Bool
+checkSeparator c = not (isDigit c) && (c /= '.')
+
+main :: IO ()
+main = do
+  content <- readFile "sample.txt"
+  let fileContent = (concat . lines) content
+  let symbols = (HashSet.fromList . getSeparators) fileContent
+  let test = (filter (/= "") . splitOn ".") fileContent
+  print symbols
+  print test
+  putStrLn "Hello, Haskell!"