Rainbow.elm

import Html as H
import Html ((:=))

intercalate : String -> [String] -> String
intercalate s ss = concat (intersperse s ss)

shadow : Float -> Float -> Float -> Float -> Float -> Float -> String
shadow x y b h s l = intercalate " " [H.px x , H.px y,  H.px b] ++ " " ++ H.color (hsl h s l)

greeting : Float -> Element
greeting t = let theta = t * (2 * pi) / 3.0
             in container 500 500 middle
                 <| H.toElement 200 200
                 <| H.node "div" []
                                 [ "color" := H.color (hsl theta 0.75 0.80)
                                 , "font-size" := H.px 60
                                 , "text-shadow" := intercalate ", " [ shadow 2 2 8 theta 0.85 0.2
                                                                     , shadow 0 0 35 theta 0.95 0.1
                                                                     ]
                                 ]
                                 [H.text "Hello Rainbow"]

frameCount : Signal Float
frameCount = let sceneFps = 25 in (sampleOn (fps sceneFps) (constant (1.0/sceneFps)))

main : Signal Element
main = greeting <~ foldp (+) 0 frameCount