haskell-practice/typecheck.hs at master · pasaunders/haskell-practice · GitHub

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module TypeCheck where


-- data Rocks = Rocks String
--   deriving (Eq, Show)
--
-- data Yeah = Yeah Bool
--   deriving (Eq, Show)
--
-- data Papu = Papu Rocks Yeah
--   deriving (Eq, Show)
--
-- phew = Papu (Rocks "chases") (Yeah True)
--
-- truth = Papu (Rocks "chomskydoz") (Yeah True)
--
-- equalityForall :: Papu -> Papu -> Bool
-- equalityForall p p' = p == p'
--
-- comparePapus :: Papu -> Papu -> Bool
-- comparePapus p p' = p > p' -- no instance of Ord, won't typecheck
--
-- type Subject = String
-- type Verb = String
-- type Object = String
--
-- data Sentence = Sentence Subject Verb Object
--   deriving (Eq, Show)
--
-- s1 = Sentence "dogs" "drool" -- needs another string here
-- s2 = Sentence "Julie" "loves" "dogs"

-- data Mood = Blah | Woot
--   deriving Show
--
-- settleDown x = if x == Woot -- needs instance of Eq for mood
--   then Blah
--   else x
--
-- data Person = Person Bool
--
-- printPerson :: Person -> IO()
-- printPerson person = putStrLn (show person) -- needs instance of show for person