private IEnumerator <EvaluationNode> EvaluationTree(Expression expression, EvaluationNode parentNode)
{
ListStack evaluationstack = new ListStack();
EvaluationNode prevNode = null;
for (int j = 0; j < expression.ExpressionStack.Count; j++)
{
Expression e = expression.ExpressionStack[j];
if (e.Valuable)
{
evaluationstack.Push(e);
}
else
{
Expression[] values = new Expression[e.ArgumentsCount];
if (expression.ExpressionStack.Count < e.ArgumentsCount)
{
throw new EvaluateException("Syntax Error");
}
for (int i = e.ArgumentsCount - 1; i >= 0; i--)
{
values[i] = evaluationstack.Pop();
}
evaluationstack.Push(e);
prevNode = new EvaluationNode()
{
Node = e, Params = values, Prevoius = prevNode, ParentNode = parentNode
};
yield return(prevNode);
if (e.InnerStack)
{
IEnumerator <EvaluationNode> enChild = e.EvaluationTree(e, prevNode);
while (enChild.MoveNext())
{
EvaluationNode childNode = enChild.Current;
yield return(childNode);
}
}
}
}
}
internal object Evaluate(object[] variables, out bool evaluated)
{
evaluated = true;
ListStack evaluationstack = new ListStack();
for (int j = 0; j < ExpressionStack.Count; j++)
{
Expression e = ExpressionStack[j];
if (e.Valuable)
{
VariableExpression v = e as VariableExpression;
if (v != null)
{
e = new ConstExpression(variables[v.Ordinal]);
}
evaluationstack.Push(e);
}
else
{
Expression[] values = new Expression[e.ArgumentsCount];
if (ExpressionStack.Count < e.ArgumentsCount)
{
throw new EvaluateException("Syntax Error");
}
for (int i = e.ArgumentsCount - 1; i >= 0; i--)
{
values[i] = evaluationstack.Pop();
}
evaluated = true;
Expression[] ret = e.Evaluate(values, out evaluated);
if (evaluated && ret != null)
{
for (int i = 0; i < ret.Length; i++)
{
evaluationstack.Push(ret[i]);
}
}
else
{
break;
}
}
}
if (evaluated)
{
if (evaluationstack.Count == 1)
{
if (evaluationstack[0].NumericValue.HasValue)
{
return(evaluationstack[0].NumericValue.Value);
}
else if (evaluationstack[0].BoolValue.HasValue)
{
return(evaluationstack[0].BoolValue.Value);
}
else if (evaluationstack[0].ArrayValue != null)
{
return(evaluationstack[0].ArrayValue);
}
else if (evaluationstack[0].DataTimeValue != null)
{
return(evaluationstack[0].DataTimeValue);
}
else if (evaluationstack[0].StringValue != null)
{
return(evaluationstack[0].StringValue);
}
else
{
return(null);
}
}
else
{
throw new EvaluateException("Syntax Error");
}
}
else
{
return(null);
}
}