functions.elm

import Graphics.Element exposing (show)
import Graphics.Collage exposing (collage, filled, move, ngon)
import Color exposing (green, purple)

-- function(http://elm-lang.org/examples/functions)
four =
  sqrt 16

eleven =
  max 2 11

twenty =
  max (sqrt 100) (4 * 5)

-- main =
--   show [four, eleven, twenty] -- [4,11,20]

-- infix(http://elm-lang.org/examples/infix)
five =
  2 + 3

sixteen =
  8 * 2

ten =
  (4 * 3) - 2

thirteen =
  4 * 3 + 1

isTeenage age =
  (age > 12) && (age < 20)

isTeenage' age =
  age > 12 && age < 20

-- main =
--   show
--   [ isTeenage four
--   , isTeenage sixteen
--   , isTeenage eleven
--   , isTeenage thirteen
--   ] -- [False,True,False,True]

-- use fewer parens(http://elm-lang.org/examples/forward-apply)
-- main =
--   collage 200 200 [purplePentagon, greenPentagon]

purplePentagon =
  move (20, 20) (filled purple (ngon 5 50))

greenPentagon =
  ngon 5 50
    |> filled green
    |> move (-20, -20)

-- define function(http://elm-lang.org/examples/define-functions)
add x y =
  x + y

factorial n =
  List.product [1..n]

-- main =
--   show (add 1 (factorial 4)) -- 25