elm start app

yeahok.elm

import Html exposing (div, button, text)
import Html.Events exposing (onClick)
import StartApp.Simple as StartApp

main : Signal Html.Html
main =
  StartApp.start { model = model, view = view, update = update }

model : Int
model = 0

view : Signal.Address Action -> a -> Html.Html
view address model =
  div [ ]
        [ div [] [ text (toString model) ]
        , button [ onClick address Decrement ] [ text "-" ]
        , button [ onClick address Increment ] [ text "+" ]
        , button [ onClick address Reset ] [ text " RESET " ]
        , button [ onClick address Double ] [ text " dub " ]
        , button [ onClick address Triple ] [ text " trip " ]
        ]

type Action = Increment
            | Decrement
            | Reset
            | Double
            | Triple

mult : number -> number -> number
mult x y =
  x * y

triple : number -> number
triple x =
  mult 3 x

double : number -> number
double x =
  mult 2 x

update : Action -> number -> number
update action model =
  case action of
    Increment -> model + 1
    Decrement -> model - 1
    Reset     -> 0
    Double    -> double model
    Triple    -> triple model