private static Event <TA> SwitchE <TA>(Transaction trans1, Behavior <Event <TA> > bea)
{
var @out = new EventSink <TA>();
var h2 = new TransactionHandler <TA>
{
Run = (trans2, a) => @out.Send(trans2, a)
};
var h1 = new TransactionHandler <Event <TA> > {
CurrentListener = bea.SampleNoTrans().Listen(@out.Node, trans1, h2, false)
};
h1.Run = (trans2, ea) => trans2.Last(
new Runnable
{
Run = () =>
{
if (h1.CurrentListener != null)
{
h1.CurrentListener.Unlisten();
}
h1.CurrentListener = ea.Listen(@out.Node, trans2, h2, true);
}
});
Listener l1 = bea.Updates().Listen(@out.Node, trans1, h1, false);
return(@out.AddCleanup(l1));
}
///
///Unwrap a behavior inside another behavior to give a time-varying behavior implementation.
///
public static Behavior <TA> SwitchB <TA>(Behavior <Behavior <TA> > bba)
{
Func <TA> za = () => bba.SampleNoTrans().SampleNoTrans();
var @out = new EventSink <TA>();
var h = new TransactionHandler <Behavior <TA> >();
h.Run = (trans2, ba) =>
{
// Note: If any switch takes place during a transaction, then the
// value().listen will always cause a sample to be fetched from the
// one we just switched to. The caller will be fetching our output
// using value().listen, and value() throws away all firings except
// for the last one. Therefore, anything from the old input behaviour
// that might have happened during this transaction will be suppressed.
if (h.CurrentListener != null)
{
h.CurrentListener.Unlisten();
}
h.CurrentListener = ba.Value(trans2).Listen(
@out.Node,
trans2,
new TransactionHandler <TA>
{
Run = (trans3, a) => @out.Send(trans3, a)
},
false);
};
Listener l1 = bba.Value().Listen_(@out.Node, h);
return(@out.AddCleanup(l1).HoldLazy(za));
}
public ListenerImplementation(Event <TA> @event, TransactionHandler <TA> action, Node target)
{
_event = @event;
this.action = action;
this.target = target;
Unlisten = UnlistenImpl;
}
///
///Merge two streams of events of the same type.
///
///In the case where two event occurrences are simultaneous (i.e. both
///within the same transaction), both will be delivered in the same
///transaction. If the event firings are ordered for some reason, then
///their ordering is retained. In many common cases the ordering will
///be undefined.
///
public static Event <TA> Merge <TA>(Event <TA> ea, Event <TA> eb)
{
var @out = new EventSink <TA>
{
SampleNow = () =>
{
Object[] oa = ea.SampleNow();
Object[] ob = eb.SampleNow();
if (oa != null && ob != null)
{
var oo = new Object[oa.Length + ob.Length];
int j = 0;
for (int i = 0; i < oa.Length; i++)
{
oo[j++] = oa[i];
}
for (int i = 0; i < ob.Length; i++)
{
oo[j++] = ob[i];
}
return(oo);
}
if (oa != null)
{
return(oa);
}
return(ob);
}
};
var h = new TransactionHandler <TA>
{
Run = (trans, a) => @out.Send(trans, a)
};
Listener l1 = ea.Listen_(@out.Node, h);
Listener l2 = eb.Listen_(@out.Node, new TransactionHandler <TA>
{
Run = (trans1, a) => trans1.Prioritized(@out.Node, new Handler <Transaction>
{
Run = trans2 =>
{
@out.Send(trans2, a);
}
})
});
return(@out.AddCleanup(l1).AddCleanup(l2));
}
public Listener Listen(Node target, Transaction trans, TransactionHandler <TA> action, bool suppressEarlierFirings)
{
lock (Transaction.ListenersLock)
{
if (Node.LinkTo(target))
{
trans.ToRegen = true;
}
Listeners.Add(action);
}
trans.Prioritized(target, new Handler <Transaction>
{
Run = trans2 =>
{
object[] aNow = SampleNow();
if (aNow != null)
{
// In cases like value(), we start with an initial value.
foreach (object t in aNow)
{
action.Run(trans, (TA)t); // <-- unchecked warning is here
}
}
if (!suppressEarlierFirings)
{
// Anything sent already in this transaction must be sent now so that
// there's no order dependency between send and listen.
foreach (TA a in Firings)
{
action.Run(trans, a);
}
}
}
});
return(new ListenerImplementation <TA>(this, action, target));
}
public Listener Listen_(Node target, TransactionHandler <TA> action)
{
return(Transaction.Apply(trans1 => Listen(target, trans1, action, false)));
}