Add remaining haskell book exercises

2025-12-11 10:28:11 +01:00
parent 3624c712d7
commit 98329e0a3d
221 changed files with 8033 additions and 2 deletions
--- a/Haskell-book/12/Maybe.hs
+++ b/Haskell-book/12/Maybe.hs
@@ -0,0 +1,19 @@
+module Maybe where
+
+--
+-- 1
+--
+isJust :: Maybe a -> Bool
+isJust (Just _) = True
+isJust Nothing = False
+
+isNothing :: Maybe a -> Bool
+isNothing (Just _) = False
+isNothing Nothing = True
+
+--
+-- 2
+--
+mayybee :: b -> (a -> b) -> Maybe a -> b
+mayybee v f Nothing   = b
+mayybee v f (Maybe x) = f x