intro.hs

module Intro where

import Data.Char (toUpper)

x = 3
greeting = "Hello"

three :: () -> Int
three _ = 3

y = three ()

square (n) = n * n

greet name = greeting ++ ", " ++ name ++ "!"

add (x,y) = x + y

mult (x,y) = x * y

sumit ([]) = 0
sumit ((h:t)) = add (h,sumit (t))

prod ([]) = 1
prod ((h:t)) = mult (h,prod (t))

flerf (base, f, []) = base
flerf (base, f, (h:t)) = f (h, flerf (base, f, t))

power (xs) = flerf (1, (\(x,y) -> x^y), xs)

add' :: Int -> Int -> Int
add' x y = x + y

chickenCurry :: ((a,b) -> c) -> a -> b -> c
chickenCurry f = (\a -> \b -> f (a,b))

add'' = chickenCurry add

flerf' base f [] = base
flerf' base f (h:t) = f h $ flerf' base f t

power' = flerf' 1 (^)

mapit f [] = []
mapit f (h:t) = (f h):(mapit f t)

shout s = mapit toUpper s

shoutAGreeting = shout . greet
greetByShoutingName = greet . shout

data Color = Red | Green | Blue

colorToString Red = "Red"
colorToString Green = "Green"
colorToString Blue = "Blue"

data Color' = Red' | Green' | Blue' deriving (Show)

data Tree a =
  | Branch Tree a Tree
  | Leaf
  deriving (Show)