$ elm install ericgj/elm-validation

view : Form -> Html Msg
view form =
    div []
        [ input
            [ type_ "text"
            , value
                (form.input
                    |> Validation.toString identity
                )
            , onInput
                (Validation.validate isRequired
                    >> SetInput
                )
            ]
            []
        , div 
            [ class "error" ]
            [ text
                (Validation.message form.input
                    |> Maybe.withDefault ""
                )
            ]
        ]

validateForm : Form -> ValidationResult Model
validateForm form =
    Validation.valid Model
        |> Validation.andMap form.field1
        |> Validation.andMap form.field2