From 98329e0a3dd4f78b5d815ac3896272ec70904901 Mon Sep 17 00:00:00 2001 From: Eugen Wissner Date: Thu, 11 Dec 2025 10:28:11 +0100 Subject: Add remaining haskell book exercises --- Haskell-book/26/Exercises/src/Fix.hs | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Haskell-book/26/Exercises/src/Fix.hs (limited to 'Haskell-book/26/Exercises/src/Fix.hs') diff --git a/Haskell-book/26/Exercises/src/Fix.hs b/Haskell-book/26/Exercises/src/Fix.hs new file mode 100644 index 0000000..bd43f7f --- /dev/null +++ b/Haskell-book/26/Exercises/src/Fix.hs @@ -0,0 +1,24 @@ +module Fix where + +import Control.Monad.IO.Class (liftIO) +import Control.Monad.Trans.Maybe +import Control.Monad + +isValid :: String -> Bool +isValid v = '!' `elem` v + +maybeExcite :: MaybeT IO String +maybeExcite = do + v <- liftIO getLine + guard $ isValid v + return v + +doExcite :: IO () +doExcite = do + putStrLn "say something excite!" + excite <- runMaybeT maybeExcite + case excite of + Nothing -> putStrLn "MOAR EXCITE" + Just e -> + putStrLn + ("Good, was very excite: " ++ e) -- cgit v1.2.3