sequence function you can easily describe a message that calls a list of other messages. It's useful when dealing with semantics of your messages.
Example 1: You are making a game engine, and you need to refresh the screen on every frame.
module Video exposing (..) type Message = module Video exposing (..) import Update.Extra exposing (sequence) -- Model definition [...] type Message = ClearBuffer | DrawToBuffer | UpdateLogic | Update update : Message -> Model -> (Model, Cmd) update msg model = case msg of ClearBuffer -> -- do something DrawToBuffer -> -- do something UpdateLogic -> -- do something Update -> model !  |> sequence update [ ClearBuffer , DrawToBuffer , UpdateLogic]