private void BuildJoinNode(ReteBuilderContext context, IEnumerable <ConditionElement> conditions = null)
{
var betaConditions = new List <BetaCondition>();
if (conditions != null)
{
foreach (var condition in conditions)
{
var factIndexMap = FactIndexMap.CreateMap(condition.References, context.Declarations);
var betaCondition = new BetaCondition(condition.Expression, factIndexMap);
betaConditions.Add(betaCondition);
}
}
var node = context.BetaSource
.Sinks.OfType <JoinNode>()
.FirstOrDefault(x =>
x.RightSource == context.AlphaSource &&
x.LeftSource == context.BetaSource &&
ConditionComparer.AreEqual(x.Conditions, betaConditions));
if (node == null)
{
node = new JoinNode(context.BetaSource, context.AlphaSource);
foreach (var betaCondition in betaConditions)
{
node.Conditions.Add(betaCondition);
}
}
BuildBetaMemoryNode(context, node);
context.ResetAlphaSource();
}
private TerminalNode BuildTerminalNode(ReteBuilderContext context, IEnumerable <Declaration> ruleDeclarations)
{
if (context.AlphaSource != null)
{
BuildJoinNode(context);
}
var factIndexMap = FactIndexMap.CreateMap(ruleDeclarations, context.Declarations);
var terminalNode = new TerminalNode(context.BetaSource, factIndexMap);
return(terminalNode);
}
public bool IsSatisfiedBy(IExecutionContext context, Tuple leftTuple, Fact rightFact)
{
var args = new object[_compiledExpression.ParameterCount];
int index = leftTuple.Count - 1;
foreach (var fact in leftTuple.Facts)
{
FactIndexMap.SetElementAt(ref args, _conditionFactMap.Map(index), 0, fact.Object);
index--;
}
FactIndexMap.SetElementAt(ref args, _conditionFactMap.Map(leftTuple.Count), 0, rightFact.Object);
try
{
return(_compiledExpression.Delegate(args));
}
catch (Exception e)
{
context.EventAggregator.RaiseConditionFailed(context.Session, e, _expression, leftTuple, rightFact);
throw new RuleConditionEvaluationException("Failed to evaluate condition", _expression.ToString(), e);
}
}
public BetaCondition(LambdaExpression expression, FactIndexMap conditionFactMap)
{
_expression = expression;
_conditionFactMap = conditionFactMap;
_compiledExpression = FastDelegate.Create <Func <object[], bool> >(expression);
}
public Activation(ICompiledRule rule, Tuple tuple, FactIndexMap tupleFactMap)
{
_rule = rule;
_tuple = tuple;
_tupleFactMap = tupleFactMap;
}