To pass global (static) functions, we simply pass their addresses

We need to know the calling convention for all function values that can be called

var exlaim = "!!!"
 
def simpleNotify(msg : String) = {
  println(msg)
}
def noisyNotify(msg : String) = {
  beep(1024)
  popUp(msg)
  beep(2048)
  popUp(msg + exclaim)
  beep(512)
}
def alarm(time : Int, notify : msg => unit) = {
  if (currentTime==time) {
    notify("Wake up!")
  }
}
alarm(0700, simpleNotify)
alarm(0800, noisyNotify)

When 'notify' is called in 'alarm', it will be passed string argument on stack

• it knows how to access global variables

This works in e.g. C and Pascal