public virtual ComparableDict getParams()
{
ComparableDict dict = new ComparableDict();
foreach (DictionaryEntry entry in slots)
{
object slotValue = ((Slot)entry.Value).slotValue;
if (slotValue is ICloneable)
{
slotValue = ((ICloneable)slotValue).Clone();
}
dict.Add(entry.Key, slotValue);
}
return(dict);
}
public static bool consult(string ruleset, string goal, ChainingMethod method)
{
statesByRule = new ComparableDict();
firedRules = new ArrayList();
foreach (string ruleName in CSharpExpertAbstract.getRulesetFrame(ruleset).getRules().Keys)
{
statesByRule.Add(ruleName, new ArrayList());
}
if (method.Equals(ChainingMethod.backward))
{
return(backwardChaining(ruleset, goal));
}
else if (method.Equals(ChainingMethod.forward))
{
return(forwardChaining(ruleset, goal));
}
return(false);
}
public static bool forwardChaining(string rulesetName, string goal)
{
IList candidates1 = new ArrayList(); // candidates that have high proirity (first lane)
IList candidates2 = new ArrayList(); // candidates that have low priority (second lane)
RulesetFrame ruleset = CSharpExpertAbstract.getRulesetFrame(rulesetName);
if (!ruleset.isContextInitialized)
{
throw new KnowledgeException("Context of ruleset \"" + rulesetName + "\" must be initialized before consulting");
}
if (!ruleset.isParamsInitialized)
{
throw new KnowledgeException("Parameters of ruleset \"" + rulesetName + "\" must be set before consulting");
}
foreach (Rule rule in ruleset.getRules().Values)
{
if (rule.condition() == true &&
!((IList)statesByRule[rule.getName()]).Contains(ruleset.getParams()))
{
if (firedRules.Contains(rule))
{
candidates2.Add(rule);
}
else
{
candidates1.Add(rule);
}
}
}
if (candidates1.Count == 0 && candidates2.Count == 0)
{
ruleset.isContextInitialized = false;
ruleset.isParamsInitialized = false;
CSharpExpertAbstract.getOutputStream().WriteLine("Goal = \"{0}\" can't be calculated by using the set of rules \"{1}\"", goal, ruleset.getName());
return(false);
}
// method of conflict-resolution is very simple, just call first rule
ComparableDict parameters = ruleset.getParams();
Rule choosenRule = null;
if (candidates1.Count > 0)
{
choosenRule = ((Rule)candidates1[0]);
}
else if (candidates2.Count > 0)
{
choosenRule = ((Rule)candidates2[0]);
}
((IList)statesByRule[choosenRule.getName()]).Add(parameters);
object old_value_of_goal = parameters[goal];
choosenRule.if_statement(); // "if" block of chosen rule is fired
firedRules.Add(choosenRule);
if (showComments)
{
CSharpExpertAbstract.getOutputStream().WriteLine("Rule \"{0}\" has been fired:\n {1}", choosenRule.getName(), choosenRule.getComment());
}
foreach (Rule rule in ruleset.getRules().Values) // "else" blocks of all other rules are fired
{
if (rule != choosenRule)
{
rule.else_statement();
}
}
if (!ruleset.getParams()[goal].Equals(old_value_of_goal))
{
ruleset.isContextInitialized = false;
ruleset.isParamsInitialized = false;
CSharpExpertAbstract.getOutputStream().WriteLine("Goal is calculated: \"{0}\"={1}", goal, ruleset.getParams()[goal]);
return(true);
}
return(forwardChaining(rulesetName, goal));
}