Monadic composition of screens

gistfile1.txt

flow = do
  _ <- splashScreen
  l <- languageSet
  pure(l ? npciSplashScreen : ChooseLanguageScreen)


npciSplashScreen = do
  _ <- wait 0
  permission <- checkPermission
  pure(permission ? postPermission : showPermission)

postPermission = do
  t <- registrationToken
  pure(t ? rtSet : rtNotSet)

rtSet = do
  pc <- passCode
  pure(pc ? loginScreen : registerScreen)

rtNotSet = do
  nw <- networkAvailable
  isBound <- bindDevice
  guard isBound
  cs <- call