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@@ -0,0 +1,99 @@
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+module Haskell1 where
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+
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+ones = 1 : ones
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+
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+fib = 1 : 1 : [a+b | (a,b) <- zip fib (tail fib)]
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+
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+mytake 0 _ = []
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+mytake _ [] = []
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+mytake n (x:xs) = x : mytake (n-1) xs
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+
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+myfoldl f z [] = z
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+myfoldl f z (x:xs) = myfoldl f (f x z) xs
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+
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+instance Show (a -> b) where
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+ show f = "<< a function>>"
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+
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+-- define my-lenght
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+mylenght :: [a] -> Int
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+mylenght [] = 0
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+mylenght (x:xs) = 1 + mylenght xs
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+
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+myrange :: Int -> Int -> [Int]
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+myrange a b = if a > b
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+ then error "Low > High"
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+ else if a < b
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+ then a : myrange (a +1) b
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+ else [a]
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+
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+data TrafficLight = Red | Yellow | Green
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+
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+data Answer = Yes | No
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+
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+data Tree a = EmptyTree | Node a (Tree a) (Tree a)
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+
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+data Person = Person { firstname :: String
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+ , lastname :: String
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+ , age :: Int
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+ , height :: Float
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+ , phonenumber :: String
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+ }
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+
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+mymap :: (a -> b) -> [a] -> [b]
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+mymap _ [] = []
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+mymap f (x:xs) = f x : mymap f xs
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+
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+-- Re-write the myrange with boolean guards
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+
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+myrange2 :: Int -> Int -> [Int]
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+myrange2 a b
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+ | a > b = error "low > high"
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+ | a == b = [b]
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+ | a < b = a : myrange2 (a + 1) b
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+
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+-- define myrange with only one input parameter
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+
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+myrange3 :: Int -> [Int]
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+myrange3 a = a : myrange3 (a + 1)
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+
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+--describe the type of a list
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+
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+describelist :: [a] -> String
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+describelist xs = "The list is " ++ case xs of
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+ [] -> "Empty List"
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+ [x] -> "One element / Singleton"
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+ xs -> "Multiple Elements"
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+
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+
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+--definition of confitional take from list
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+
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+myTakeWhile :: (a -> Bool) -> [a] -> [a]
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+myTakeWhile _ [] = []
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+myTakeWhile f (x:xs)
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+ | f x = x : myTakeWhile f xs
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+ | otherwise = []
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+
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+myFilter :: (a -> Bool) -> [a] -> [a]
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+myFilter _ [] = []
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+myFilter c (x:xs)
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+ | c x = x : myFilter c xs
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+ | otherwise = myFilter c xs
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+
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+--define myReverse
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+
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+myReverse :: [a] -> [a]
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+myReverse = foldl (\acc x -> x:acc) []
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+
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+--define mySum, a function that sums all the elements of a list
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+
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+mySum :: [Int] -> Int
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+mySum [] = 0
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+mySum (x:xs) = x + mySum xs
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+
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+mySum2 :: (Num a)=>[a] -> a
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+mySum2 = foldl (\acc x -> acc + x) 0
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+
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+--define myFilter2 using foldr
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+
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+myFilter2 :: (a -> Bool) -> [a] -> [a]
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+myFilter2 f = foldr (\x acc -> if f x then x:acc else acc) []
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