/// <summary>
/// Associates a trigger with corresponding guards.
/// </summary>
/// <param name="trigger">The trigger to associate.</param>
private void CalculateTriggerDependencies(ProductTrigger trigger)
{
var ct = trigger.PreCondition;
var gtpost = trigger.PostCondition;
var gtpre = ct;
TraceDependencies("trigger '{0}' conditions [{1}, {2}] ...", trigger.Name, gtpre, gtpost);
if (!trigger.ModifiedVariables.Any())
{
TraceDependencies(" does not modify state.");
return;
}
foreach (var guard in Guards)
{
var gg = guard.PreCondition;
TraceDependencies(" guard '{0}' precondition [{1}] ...", guard.Name, gg);
var tg = new TriggerGuard(trigger, guard);
if (guard.Transitions.Any())
{
TraceDependencies(" state change guard ...");
if (!guard.ModifiedVariables.Intersect(trigger.ModifiedVariables).Any())
{
TraceDependencies(" no affected variable.");
continue;
}
var gatepre = Gate.ComposeAND(gtpre, gg);
if (gatepre.Type == GateType.Fixed)
{
TraceDependencies(" precondition does not match.");
continue;
}
var gatepost = Gate.ComposeAND(gtpost, guard.PostCondition);
if (gatepost.Type == GateType.Fixed)
{
TraceDependencies(" postcondition does not match.");
continue;
}
TraceDependencies(" combination ({0}, {1}) handler.", gatepre, gatepost);
tg.PreCondition = gatepre;
tg.PostCondition = gatepost;
}
else
{
TraceDependencies(" static condition [{0}] ...", gg);
Debug.Assert(guard.PreCondition.ID == guard.PostCondition.ID);
IGate genter, gleave;
if (guard.Type == GuardType.ENTER)
{
// PRE[trigger] AND NOT POST[guard]
// trigger condition met, guard condition not met
genter = Gate.ComposeAND(trigger.PreCondition, Gate.Invert(guard.PreCondition));
// PRE[trigger] AND PRE[guard]
// trigger condition met, guard conditon not met
gleave = Gate.ComposeAND(trigger.PostCondition, guard.PostCondition);
}
else
{
genter = Gate.ComposeAND(trigger.PreCondition, guard.PreCondition);
gleave = Gate.ComposeAND(trigger.PostCondition, Gate.Invert(guard.PostCondition));
}
var tgenter = genter;
var tgleave = gleave;
Gate.TraceDependencies(genter, gleave, "guard product");
// set all factors not appearing in the trigger to 1
genter = ReplaceTransitionVariables(trigger.Transitions, genter, true);
gleave = ReplaceTransitionVariables(trigger.Transitions, gleave, true);
Gate.TraceDependencies(genter, gleave, "inter product");
// set all factors not appearing in the guard to 1
genter = ReplaceNonGuardVariables(genter, guard);
gleave = ReplaceNonGuardVariables(gleave, guard);
/*genter = ReplaceTransitionVariables(guard.Transitions, genter, true);
* gleave = ReplaceTransitionVariables(guard.Transitions, gleave, true);*/
Gate.TraceDependencies(genter, gleave, "guard match");
//if (genter is FalseGate || gleave is FalseGate)
if (genter.Type.IsFixed() || gleave.Type.IsFixed())
{
TraceDependencies(" condition does not match.");
continue;
}
/*tg.PreCondition = guard.PreCondition;
* tg.PostCondition = guard.PostCondition;*/
tg.PreCondition = tgenter;
tg.PostCondition = tgleave;
Gate.TraceDependencies(tgenter, tgleave, "guard conditions");
// see if the transition set is non-empty
var transx = trigger.Transitions.Match(genter, gleave).ToArray();
if (transx.Length > 0)
{
if (guard.Type == GuardType.ENTER)
{
TraceDependencies(" entry handler.");
}
else if (guard.Type == GuardType.LEAVE)
{
TraceDependencies(" exit handler.");
}
else
{
throw new InvalidOperationException("unexpected guard type.");
}
}
else
{
TraceDependencies(" transition does not match.");
continue;
}
}
// associate the trigger with the guard and vice versa
trigger.AddGuard(tg);
}
}
internal static IGate Simplify(this IGate gate)
{
return(Gate.Simplify(gate));
}
/// <summary>
/// Adds a trigger to the state machine.
/// </summary>
/// <param name="trigger">The trigger object to add.</param>
public void AddTrigger(Trigger trigger)
{
var e = trigger.Event;
SetModify();
try
{
TraceDependencies("add trigger '{0}' ...", trigger.Name);
// ValidateTrigger(trigger);
var tlist = new List <ProductTrigger>();
// examinate the precondition ...
var precondition = trigger.PreCondition;
if (precondition.Type == GateType.Fixed)
{
// constant
if (precondition is FalseGate)
{
Trace("SMG033: warning: trigger '{0}' precondition is never met.", trigger);
}
else if (precondition is TrueGate)
{
Trace("SMG034: warning: trigger '{0}' precondition is always true.", trigger);
tlist.Add(new ProductTrigger(trigger));
}
}
else if (precondition.Type == GateType.OR)
{
// OR combination, split into multiple simple triggers
var inputs = precondition.GetInputs();
TraceDependencies("split trigger [{0}] into its branches ...", inputs.ToSeparatorList());
// analyze conditions
// TraceDependencies("{0}", trigger.Transitions.ToDebugString());
// split into multiple triggers
foreach (var product in inputs)
{
// extract the transition subset for the guard condition
var tset = new TransitionSet(trigger.Transitions, product);
TraceDependencies(" transition set of branch [{0}]: {1}", product, tset.ToDebugString());
var pre = ReplaceVariableCondition(tset, product, false);
var post = ReplaceVariableCondition(tset, product, true);
TraceDependencies(" branch conditions [{0} => {1}].", pre, post);
// add branch trigger
tlist.Add(new ProductTrigger(trigger, tset, pre, post));
}
}
else
{
// add original trigger
tlist.Add(new ProductTrigger(trigger));
}
// process resulting triggers
foreach (var t1 in tlist)
{
TraceDependencies("product trigger {0} ...", t1);
TraceDependencies(" conditions [{0}, {1}] ...", t1.PreCondition, t1.PostCondition);
TraceDependencies(" transitions {0}", trigger.Transitions.ToDebugString());
t1.Qualify();
// check if any existing trigger is conflicting
foreach (var existingtrigger in e.Triggers)
{
// the new trigger precondition must not intersect any existing precondition
var product = Gate.ComposeAND(existingtrigger.PreCondition, t1.PreCondition);
product = ReplaceTransitionVariables(existingtrigger.Transitions, product, false);
if (!product.IsFalse())
{
throw new CompilerException(ErrorCode.AmbigousPreCondition, "ambigous transition conditions [" +
existingtrigger.PreCondition + ", " + t1.PreCondition + "].");
}
}
e.Triggers.Add(t1);
}
}
catch (CompilerException ex)
{
AddError(ex);
}
}