all.hs

module Simple where

inc, increment :: Num a => a -> a
inc x = x + 1
increment x = inc x

double :: Int -> Int
double x = x * 2

exclaim :: String -> String
exclaim x = x ++ "!!"

average :: Fractional a => a -> a -> a
average a b = (a + b) / 2

-- square :: Int -> Int
square' x = x * x

showResult :: Int -> String
showResult x = "The result is " ++ (show x)

areaOfCircle :: Float -> String
areaOfCircle f =
    "r = " ++ (show f) ++ " == " ++ (show (pi * (f^2))) ++ "cm^2"

circleArea' :: Floating a => a -> a 
circleArea' x = pi * radius * radius 
    where
        radius = x / 2.0

addMul :: Num a => a -> a -> (a,a)
addMul x y = (x+y, x*y)

maxNum :: Ord a => a -> a -> a
maxNum x y = if x >= y then x else y

-- ---

type Point = (Int, Int)

-- origin :: Point
-- origin = (0, 0)

moveRight :: Point -> Int -> Point
moveRight (x,y) z = (x+z, y)

moveUp :: Point -> Int -> Point
moveUp (x,y) z = (x, y+z)

type Colour = String
type ColourPoint = (Int, Int, Colour)

c1 = (10, 10, "red")
c2 = (90, 90, "yellow")

colourOfPoint :: ColourPoint -> String
colourOfPoint (x, y, c) = c

origin :: Colour -> ColourPoint
origin colour = (0, 0, colour)

moveColourPoint :: ColourPoint -> Int -> Int -> ColourPoint
moveColourPoint  (x,y,c) dx dy = (x+dx,y+dy,c)

distanceBetween :: ColourPoint -> ColourPoint -> Float
distanceBetween (x1,y1,c1) (x2,y2,c2)
    = sqrt(fromIntegral (dx * dx + dy * dy))
    where
        dx = x2 - x1
        dy = y2 - y1