subscribed source code

1 /// A minimalistic library providing eventing-related structures.
2 module subscribed;
3 
4 /// <a href="./event.html">Go to the docs for the Event struct.</a>
5 public import subscribed.event;
6 
7 /// <a href="./event_machine.html">Go to the docs for the EventMachine struct.</a>
8 public import subscribed.event_machine;
9 
10 /// <a href="./mediator.html">Go to the docs for the Mediator struct.</a>
11 public import subscribed.mediator;
12 
13 ///
14 unittest
15 {
16     // Create and instantiate a simple finite-state machine structure.
17     enum SimpleState { running, stopped }
18     alias SimpleMachine = EventMachine!SimpleState;
19     SimpleMachine machine;
20 
21     // Create and instantiate a simple mediator.
22     enum SimpleEvent { reset, increment }
23     alias SimpleMediator = Mediator!(
24         SimpleEvent.reset, void delegate(),
25         SimpleEvent.increment, void delegate(int)
26     );
27     SimpleMediator mediator;
28 
29     // Initialize a counter
30     int counter;
31 
32     // Bind some events to the mediator.
33     mediator.on!(SimpleEvent.reset)(() {
34         counter = 0;
35     });
36 
37     mediator.on!(SimpleEvent.increment)((int amount) {
38         counter += amount;
39     });
40 
41     // Make sure nothing happens while the machine is not running.
42     // The listeners are only ran if the beforeEach hooks all return true.
43     mediator.beforeEach ~= (SimpleEvent channelName) {
44         return channelName == SimpleEvent.reset || machine.state == SimpleState.running;
45     };
46 
47     // Bind some events to the machine state changes.
48     machine.on!(SimpleState.stopped)(() {
49         mediator.emit!(SimpleEvent.reset);
50     });
51 
52     // Experiment with different operations.
53     machine.go!(SimpleState.running)();
54     mediator.emit!(SimpleEvent.increment)(5);
55     mediator.emit!(SimpleEvent.increment)(3);
56 
57     assert(counter == 8, "The counter has not incremented");
58 
59     machine.go!(SimpleState.stopped)();
60     assert(counter == 0, "The counter was not reset by the machine");
61 
62     mediator.emit!(SimpleEvent.increment)(3);
63     assert(counter == 0, "The counter has incremented despite the machine being stopped");
64 }