private static Rule TryRuleBase(ExpressionBase RuleBase, Fact Goal)
{
return((Rule)RuleBase.FindExpression((rule) => TryThenExpression((Fact)((Rule)rule).ThenExpression, Goal)));
}
private static Fact TryFactBase(ExpressionBase FactBase, Fact Goal)
{
return((Fact)FactBase.FindExpression((fact) => fact.IsEqualTo(Goal)));
}
private static bool TryThenExpression(Fact ThenExpression, Fact Goal)
{
return(ThenExpression.IsEqualTo(Goal));
}
private static MyTreeNode SearchIntoDepth(KnowledgeBase KB, Fact Goal)
{
if (++StepCount > MaxStepCount)
{
StepCount--; return(null);
}
MyTreeNode Res = new MyTreeNode(Goal);
if (Goal.LeftArg.Type == ExpressionType.Fact)
{
if (Goal.RightArg.Type == ExpressionType.Fact) // Если искомое выражение составное
{
if (Goal.Name == Library.StandartOperations[0].ToString())
{
MyTreeNode TR = SearchIntoDepth(KB, (Fact)Goal.RightArg);
MyTreeNode TL = TR != null?SearchIntoDepth(KB, (Fact)Goal.LeftArg) : null;
StepCount--;
return(TL != null ? new MyTreeNode(Goal, TR, TL) : null);
}
if (Goal.Name == Library.StandartOperations[1].ToString())
{
MyTreeNode TR = SearchIntoDepth(KB, (Fact)Goal.RightArg);
MyTreeNode TL = SearchIntoDepth(KB, (Fact)Goal.LeftArg);
StepCount--;
return(((TL != null) || (TR != null)) ? new MyTreeNode(Goal, TR, TL) : null);
}
Res.Left = SearchIntoDepth(KB, (Fact)Goal.LeftArg);
Res.Right = SearchIntoDepth(KB, (Fact)Goal.RightArg);
}
else
{
throw new Exception("Невозможно осуществить операцию \"" + Goal.Name + "\" между фактом и не-фактом");
}
}
else
if (Goal.RightArg.Type == ExpressionType.Fact)
{
throw new Exception("Невозможно осуществить операцию \"" + Goal.Name + "\" между фактом и не-фактом");
}
else
{ // Если искомое выражение - простой факт
Res.SelfWay = new MyTreeNode(TryFactBase(KB.BaseOfFacts, Goal));
if (Res.SelfWay.Value == null)
{
foreach (EBCell cell in KB.BaseOfRules)
{
Rule rul = (Rule)cell.Value;
if (rul.ThenExpression.IsEqualTo(Goal))
{
Res.SelfWay = SearchIntoDepth(KB, (Fact)rul.IfExpression);
if (Res.SelfWay == null)
{
continue;
}
}
}
}
}
StepCount--;
if (Res.SelfWay == null)
{
if ((Res.Left == null) && (Res.Right == null))
{
return(null);
}
else
{
;
}
}
else
if (Res.SelfWay.Value == null)
{
return(null);
}
return(Res);
}