def App.loop
import Base3174def App.loop(~S: Type, ~app: App<S>, fuel: Nat, window: Window, state: S) ->
3175 IO(Unit):
3176 match fuel:
3177 case 0n:
3178 Window.close(window)
3179 case 1n+f:
3180 App.step(S, app, window, state, w => s => App.loop(~S, ~app, f, w, s))