Model -> ( Model, Cmd Msg ) update msg model = case msg of -- ③ Cmd が返したGotArticle というMsg と共に結果を受け取りモデル更新 GotArticle result -> case result of Ok articleData -> ( { model | response = Success articleData }, Cmd.none ) Err _ -> ( { model | response = Failure }, Cmd.none ) -- ② GetArticle を受け取ったらContentfulAPI を呼び出す(Cmd 発⾏) GetArticle slug -> ( model, Contentful.getArticle GotArticle slug )