App.elm

module App exposing (..)

import Html exposing (Html, button, div, text, program)
import Html.Events exposing (onClick)


-- MODEL

type alias Model =
  Int

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


-- MESSAGES

type Msg
  = Increment Int


-- VIEW

view : Model -> Html Msg
view model =
  div []
      [ button [ onClick (Increment 2) ] [ text "+" ]
      , text (toString model)
      ]


-- UPDATE

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    Increment howMuch ->
      ( model + howMuch, Cmd.none )


-- SUBSCRIPTIONS

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


-- MAIN

main : Program Never Model Msg
main =
  program
    { init = init
    , view = view
    , update = update
    , subscriptions = subscriptions
    }