public void makeSubscription(int car)
{
Contract.Requires(car != 0);
//Cars can't have two subscriptions and the list needs room to add cars...
//For all subscribers, none can equal the car
Contract.Requires(Contract.ForAll(0, SubscriberList.Length, i => !SubscriberList[i].Equals(car)), ": That car is already subscribed.");
Contract.Requires(SubscriberList.Contains(0), ": No more space on the subsciber list");
Contract.Ensures(SubscriberList.Contains(car));
Contract.Ensures(Contract.ForAll(0, SubscriberList.Length, i => SubscriberList[i].Equals(Contract.OldValue(SubscriberList[i])) ||
SubscriberList[i].Equals(car)));
}
public void enterReservedArea(int car)
{
Contract.Requires(car != 0, ": The car can't be 0");
Contract.Requires(car < 1000, ": The car can't be greater than 999");
//The car needs a subscription and the car park can't contain duplicates..
Contract.Requires(SubscriberList.Contains(car), ": The car doesn't have a subscription.");
Contract.Requires(Contract.ForAll(0, Spaces.Length, i => !Spaces[i].Equals(car)), ": The car park can't contain duplicate cars.");
Contract.Requires(CarParkIsOpen, ": The car park is closed");
//Requires that the barrier is down and the number of remaining spaces is equal to the number of cars that are
//subscribed to a reserved space.
//OR
//The the car park isn't full.
Contract.Requires(BarrierIsOpen == false && Spaces.Length - NumberParked - IDIOT_SPACES >= SubscriberList.Length ||
Spaces.Length - NumberParked - IDIOT_SPACES - SubscribersParked > 0, ": The car park is full.");
//Ensures that the array contains the car and that the rest of the array is unchanged.
Contract.Ensures(Spaces.Contains(car));
Contract.Ensures(Contract.ForAll(0, Spaces.Length, i => Spaces[i].Equals(Contract.OldValue(Spaces[i])) ||
Spaces[i].Equals(car)));
}