Sierpinski gasket with Elm

fractal.png

gistfile1.elm

import Text

main : Element
main = color blue <| collage 500 500 <| [scale 250 <| gasket yellow 7]

gasket : Color -> Int -> Form
gasket c n = 
  let
    s3 = sqrt 3
  in
    if | n <= 0 ->
          filled c <| polygon [(0,0), (1,0), (1/2, s3/2)]
       | otherwise -> 
         let
           g = scale (1/2) <| gasket c (n - 1)
         in
           group [
             g
           , move (1/2, 0)    <| g  
           , move (1/4, s3/4) <| g
           ]