Elm:
Scaricare una pagina web

import Http
import Html exposing (Html, text)
import Json.Decode as Decode

type Msg = GotText String | RequestFailed Http.Error

type alias Model = 
    { content : String
    , error : Maybe String
    }

init : ( Model, Cmd Msg )
init =
    ( { content = "", error = Nothing }
    , fetchPage "https://example.com"
    )

fetchPage : String -> Cmd Msg
fetchPage url =
    Http.get
        { url = url
        , expect = Http.expectString GotText
        }

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        GotText text ->
            ( { model | content = text, error = Nothing }, Cmd.none )

        RequestFailed err ->
            ( { model | error = Just (toString err) }, Cmd.none )

view : Model -> Html Msg
view model =
    case model.error of
        Just err ->
            text ("Request failed: " ++ err)

        Nothing ->
            text model.content