private static void RewriteNodes(OperNode oper, double operRes)
{
ValueNode resNode = new ValueNode(operRes);
if (oper.NextOper != null)
{
oper.NextOper.LeftVal = resNode;
oper.NextOper.PrevOper = oper.PrevOper;
}
if (oper.PrevOper != null)
{
oper.PrevOper.RightVal = resNode;
oper.PrevOper.NextOper = oper.NextOper;
}
}
private static void CreateNodes(string value, string operType, int operWeight, ref OperNode lastOper)
{
double dVal = 0;
if (!string.IsNullOrEmpty(value))
{
dVal = GetValue(value);
}
ValueNode valNode = new ValueNode(dVal);
OperNode oper = new OperNode(operType, operWeight, valNode, lastOper);
if (lastOper != null)
{
lastOper.RightVal = valNode;
lastOper.NextOper = oper;
}
lastOper = oper;
_operList.Add(oper);
}
private static void Parse(string expression)
{
_operList = new List <OperNode>();
int operWeight = 1;
int factor = 1;
string value = "";
OperNode lastOper = null;
for (int i = 0; i < expression.Length; ++i)
{
double dVal = 0;
string operType = expression[i].ToString();
switch (operType)
{
case "-":
case "+":
operWeight = 1 * factor;
CreateNodes(value, operType, operWeight, ref lastOper);
value = "";
break;
case "/":
case "*":
operWeight = 2 * factor;
CreateNodes(value, operType, operWeight, ref lastOper);
value = "";
break;
case "=":
dVal = GetValue(value);
ValueNode valNode = new ValueNode(dVal);
if (lastOper != null)
{
lastOper.RightVal = valNode;
lastOper.NextOper = null;
}
break;
case "(":
factor *= 4;
break;
case ")":
factor /= 4;
if (operWeight < 1)
{
throw new ArgumentException("Invalid brackets");
}
break;
default:
value += operType;
break;
}
}
if (factor != 1)
{
throw new ArgumentException("Invalid brackets");
}
}
