How to achieve behavior of setTimeout in Elm

One thing that may not be obvious at first is the fact that subscriptions can change based on the model. They are effectively evaluated after every update. You can use this fact, coupled with some fields in your model, to control what subscriptions are active at any time.

Here is an example that allows for a variable cursor blink interval:

subscriptions : Model -> Sub Msg
subscriptions model =
    if model.showCursor
        then Time.every model.cursorBlinkInterval (always ToggleCursor)
        else Sub.none

If I understand your concerns, this should overcome the potential for handling unnecessary ticks. You can have multiple subscriptions of different intervals by using Sub.batch.

An updated and simplified version of @wintvelt's answer for Elm v0.18 is:

delay : Time.Time -> msg -> Cmd msg
delay time msg =
  Process.sleep time
  |> Task.perform (\_ -> msg)

with the same usage