Main.elm

import Html exposing (..)
import Html.App as App
import Html.Events exposing (..)
import List
import Json.Decode as Json

join : List String -> String
join list = (List.foldr (++) "" list)

main : Program Never
main = App.program
  { init = init
  , view = view
  , update = update
  , subscriptions = subscriptions}

type alias Model =
  {blue: Int, red: Int}

init : (Model, Cmd Msg)
init = (Model 0 0, Cmd.none)

type Player
  = Red | Blue

type Msg
  = Player.Red | Player.Blue | Noop

update : Msg -> Model -> (Model, Cmd Msg)
update message model =
  case message of
    Player.Blue ->
      (Model (model.blue + 1) model.red, Cmd.none)
    Player.Red ->
      (Model model.blue (model.red + 1), Cmd.none)
    Noop ->
      (model, Cmd.none)

subscriptions: Model -> Sub Msg
subscriptions model = Sub.none

keyCodeToMsg : Int -> Msg
keyCodeToMsg keyCode =
  case keyCode of
    83 -> Player.Blue
    79 -> Player.Red
    _ -> Noop

onKeyCode : (Int -> msg) -> Attribute msg
onKeyCode message =
  on "keydown" (Json.map message keyCode)

view : Model -> Html Msg
view model =
  div [ onKeyCode keyCodeToMsg ]
  [ h1 [] [ text "Arm Wrestling" ]
  , p [] [text ("Blue: " ++ (toString model.blue) ++ "  Red: " ++ (toString model.red))]]