Lunch and learn demo on Elm

demo.elm

module Demo exposing (..)

import Html exposing (..)
import Html.Attributes exposing (..)
import Html.Events exposing (..)


main =
    Html.beginnerProgram
        { model = model
        , view = view
        , update = update
        }


type alias Model =
    { count : Int }


model =
    { count = 0 }


type Msg
    = CountChanged String


view : Model -> Html Msg
view model =
    let
        nums =
            List.range 0 model.count

        showNum n =
            li [] [ text (toString n) ]
    in
        div []
            [ input [ onInput CountChanged ] []
            , ul [] (nums |> List.map showNum)
            ]


update : Msg -> Model -> Model
update msg model =
    case msg of
        CountChanged str ->
            { model | count = str |> String.toInt |> Result.withDefault 0 }