September Morn Update

Task/Substring/Haskell/substring-2.hs

@@ -1,8 +1,10 @@
-import qualified Data.Text as T
-       (Text, take, drop, init, breakOn, pack, unpack)
+{-# LANGUAGE OverloadedStrings #-}
 
-fromNforM :: Int -> Int -> T.Text -> T.Text
-fromNforM n m s = T.take m (T.drop n s)
+import qualified Data.Text as T (Text, take, drop, init, breakOn)
+import qualified Data.Text.IO as O (putStrLn)
+
+fromMforN :: Int -> Int -> T.Text -> T.Text
+fromMforN n m s = T.take m (T.drop n s)
 
 fromNtoEnd :: Int -> T.Text -> T.Text
 fromNtoEnd = T.drop
@@ -10,21 +12,20 @@ fromNtoEnd = T.drop
 allButLast :: T.Text -> T.Text
 allButLast = T.init
 
-fromCharForM :: T.Text -> Int -> T.Text -> T.Text
-fromCharForM needle m haystack = T.take m $ snd (T.breakOn needle haystack)
+fromCharForN, fromStringForN :: Int -> T.Text -> T.Text -> T.Text
+fromCharForN m needle haystack = T.take m $ snd $ T.breakOn needle haystack
 
-fromStringForM :: T.Text -> Int -> T.Text -> T.Text
-fromStringForM = fromCharForM
+fromStringForN = fromCharForN
 
--- TEST -----------------------------------------------------------------------
+-- TEST ---------------------------------------------------
 main :: IO ()
 main =
   mapM_
-    (putStrLn . T.unpack)
-    ([ fromNforM 9 10
+    O.putStrLn
+    ([ fromMforN 9 10
      , fromNtoEnd 20
      , allButLast
-     , fromCharForM (T.pack "话") 6
-     , fromStringForM (T.pack "大势") 6
+     , fromCharForN 6 "话"
+     , fromStringForN 6 "大势"
      ] <*>
-     [T.pack "天地不仁仁者人也🐒话说天下大势分久必合🍑合久必分🔥"])
+     ["天地不仁仁者人也🐒话说天下大势分久必合🍑合久必分🔥"])