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authorEugen Wissner <belka@caraus.de>2025-12-11 10:28:11 +0100
committerEugen Wissner <belka@caraus.de>2025-12-11 10:28:11 +0100
commit98329e0a3dd4f78b5d815ac3896272ec70904901 (patch)
tree80f9c56cfe2ac20232358f236d32e84bd683be1b /Haskell-book/12/Maybe.hs
parent3624c712d72d246f21d4e710cec7c11e052e0326 (diff)
downloadbook-exercises-98329e0a3dd4f78b5d815ac3896272ec70904901.tar.gz
Add remaining haskell book exercises
Diffstat (limited to 'Haskell-book/12/Maybe.hs')
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diff --git a/Haskell-book/12/Maybe.hs b/Haskell-book/12/Maybe.hs
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+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