See https://discourse.elm-lang.org/t/is-tea-a-comonad/527/5

ControlBar.elm

module Editor.ControlBar exposing (Button, Config, view)

import Animation exposing (Interpolation, Property, State, percent, px)
import Html exposing (Html, div, i, li, span, text, ul)
import Html.Attributes exposing (class, href)
import Html.Events exposing (onClick)


type alias Config msg =
    { buttons : List Button
    , barDivClass : String
    , style : List Animation.Property
    , easing : Interpolation
    , onSelectName : String -> msg
    }


type alias Button =
    { name : String, iconClass : String }


view : Config msg -> Maybe Animation.State -> Html msg
view { buttons, barDivClass, onSelectName } maybeAnimation =
    let
        baseStyles =
            case maybeAnimation of
                Just state ->
                    Animation.render state

                Nothing ->
                    []
    in
    div
        (baseStyles ++ [ class barDivClass ])
        (List.map (viewButton onSelectName) buttons)



-- INTERNAL --


viewButton : (String -> msg) -> Button -> Html msg
viewButton onSelectName { name, iconClass } =
    i [ class iconClass, onClick (onSelectName name) ] []