Add remaining haskell book exercises

1 files changed, 24 insertions, 0 deletions

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
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+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)