Elm:
ウェブページのダウンロード

module Main exposing (..)

import Browser
import Html exposing (text)
import Http

type alias Model =
    { content : String }

type Msg
    = Fetch
    | FetchComplete String

init : () -> (Model, Cmd Msg)
init _ =
    ({ content = "" }, Cmd.none)

update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
    case msg of
        Fetch ->
            ( model
            , Http.get
                { url = "https://example.com"
                , expect = Http.expectString FetchComplete
                }
            )

        FetchComplete content ->
            ({ model | content = content }, Cmd.none)

view : Model -> Html.Html Msg
view model =
    text model.content

main : Program () Model Msg
main =
    Browser.element
        { init = init
        , update = update
        , view = view
        , subscriptions = \_ -> Sub.none
        }