import SimplePrelude hiding ((.), curry, uncurry, const)

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

-- Combinators: take some functions and yield another function

-- Function composition: combine two functions sequentially
(.) :: (b -> c) -> (a -> b) -> (a -> c)
g . f = \x -> g (f x)

-- Add the ASCII values of all uppercase letters in a string:
sumUC :: String -> Int
sumUC = sum . filter (\c -> c>64 && c<91) . map ord

-- Transform a function on pairs into a curryfied function:
curry :: ((a,b) -> c) -> a -> b -> c
--curry f = \x y -> f (x,y)
curry f x y = f (x,y)

uncurry :: (a -> b -> c) -> (a,b) -> c
uncurry f (x,y) = f x y

-- Scalar product: add all products of pairwise elements in two vectors:
scalar :: [Int] -> [Int] -> Int
scalar xs ys = sum (map (uncurry (*)) (zip xs ys))

-- The constant function where the first argument is the constant value:
const :: a -> b -> a
const x _ = x