Has Pre kek 0.1

prekek.hs

-- Int : 1,2,3,..
data Qwe = Non1 | Non2 deriving( Show )

data As = AA Int | SS Qwe deriving( Show )

----data As2 a = AAA (Just Int) | SSS (Just Qwe)
data As2 = AAA (Maybe Int) | SSS (Maybe Qwe) deriving( Show )
----f :: Int of Qwe -> (Maybe Int or Maybe Qwe)
f :: As -> As2
f (AA a) = AAA (Just a)
f (SS Non1) = SSS Nothing
f (SS a) = SSS (Just a)


------------------

-- data Tt a = AAAt (a Int) | SSSt (a Qwe) 
data As2' a = AAA' (a Int) | SSS' (a Qwe)

-- f' :: As -> (Int -> a Int) -> As2' a
-- f' :: As -> (Int -> Maybe Int) -> As2' Maybe
-- f' :: As -> (b -> (a -> b) -> Maybe a -> b) -> As2' Maybe
-- f' (AA a) b = AAA' (b a)
-- f' (SS a) b = SSS' (b a)
-- f' (SS Non1) b = SSS' b

-- let res1 = f' (AA 5) Just
-- let res2 = f' (AA 5) Nothing
f'' a b = (b a) -- = h -- (если b типа (a->b a))
f' (AA a) b = AAA' (b a) --(если b типа (a->b a))
-- f' (AA a) b = AAA' (b) --(если b не типа (a->b a)) или (если b типа (b a))


-- g = f' (AA 5) Just
-- g2 = f' (AA 5) Nothing


-- f' :: As -> As2' Maybe
-- f' (AA a) = AAA' (Just a)
-- f' (SS Non1) = SSS' Nothing
-- f' (SS a) = SSS' (Just a)


--===============================

-- data Maybe a = Just a | Nothing
data Maybe2 a = Just2 a | Nothing2

-- let res1 = h 5 Just -- == Just 5
-- let res2 = h 5 Nothing -- == Nothing
-- или хотябы let res2 = h Nothing (5) опцион парам -- == Nothing

h :: Int -> (Int -> Maybe Int) -> Maybe Int
-- h _ Nothing = Nothing
h a b = b a

h2 :: Int -> (Maybe Int) -> Maybe Int
h2 _ Nothing = Nothing