mkock

// Prospect is a potential Passenger. Prospects wait at BusStops to board Buses.
type Prospect struct {
	SSN string
	Destination *BusStop
}

// BusStop represents a place where a Bus can stop and signal to prospects (future passengers)
// that they may board.
type BusStop struct {
	Name string

mkock

// NotifyProspectArrival is called whenever a prospect arrives at Busstop.
func (b *BusStop) NotifyProspectArrival(p Prospect) {
	b.prospects = append(b.prospects, p)
	// Notify all Busses on this route.
	for _, bus := range b.busses {
		if bus.StopsAt(p.Destination) {
			bus.NotifyBoardingIntent(b)
		}
	}
}

mkock

// NotifyBoardingIntent is called by BusStop every time a Prospect arrives and instructs the Bus to signal its arrival at that BusStop. 
func (b *Bus) NotifyBoardingIntent(busStop *BusStop) {
	if b.StopsAt(busStop) {
		return // We already intend to stop here.
	}
	b.addBusStop(busStop)
}

mkock

// NotifyArrival notifies the current BusStop that the Bus has arrived.
func (b *Bus) NotifyArrival() {
	curr := b.stops[b.currentStop]
	curr.NotifyBusArrival(b)
}

mkock

// Bus carries Passengers from A to B if they have a valid bus ticket.
type Bus struct {
	name string
	passengers Passengers
	stops []*BusStop
	currentStop int16
}

mkock

// StopsAt checks if Bus stops at the given BusStop, and returns true if it does, and false otherwise.
func (b Bus) StopsAt(busStop *BusStop) bool {
	for _, stop := range b.stops {
		if stop.Equals(busStop) { // Some kind of equality check, anyway.
			return true
		}
	}
	return false
}

mkock

// NewBus returns a new Bus with an empty passenger set.
func NewBus(name string) Bus {
	b := Bus{}
        b.name = name
	b.currentStop = -1
	b.passengers = NewPassengerSet()
	return b
}

mkock

// NotifyBusArrival is called by Bus upon arrival.
func (b *BusStop) NotifyBusArrival(bus *Bus) {
	for _, p := range b.prospects {
		if bus.StopsAt(p.Destination) {
			bus.Add(p.ToPassenger())
		}
	}
}

// Equals returns true if the given BusStop is the same as the receiver.

mkock

// ToPassenger returns a Passenger with the same SSN as his or her Prospect.
func (p Prospect) ToPassenger() Passenger {
	return Passenger{SSN: p.SSN, , Destination: p.Destination}
}

mkock

func main() {
	fmt.Println("Starting simulation")
	expressLine := busservice.NewBus("Express Line")

	s1 := busservice.BusStop{Name: "Downtown"}
	s2 := busservice.BusStop{Name: "The University"}
	s3 := busservice.BusStop{Name: "The Village"}

	expressLine.AddStop(&s1)
	expressLine.AddStop(&s2)