(#599) Get rid of T.last from MarkovMain

Author: rexim

src/MarkovMain.hs

@@ -13,11 +13,14 @@ import System.Environment
 import Text.InterpolatedString.QM
 
 asteriskCorrectionFilter :: [T.Text] -> [T.Text]
-asteriskCorrectionFilter = filter ((/= '*') . T.last)
+asteriskCorrectionFilter = filter $ lastIsNot '*'
 
 firstIsNot :: Char -> T.Text -> Bool
 firstIsNot x = maybe False ((/= x) . fst) . T.uncons
 
+lastIsNot :: Char -> T.Text -> Bool
+lastIsNot x s = T.findIndex (== x) s /= Just (T.length s - 1)
+
 mentionsFilter :: [T.Text] -> [T.Text]
 mentionsFilter =
   filter (not . T.null) . map (T.unwords . filter (firstIsNot '@') . T.words)