private CalcResult ActualSolve(string postfix)
{
List <string> tokens = new List <string> (postfix.Split(new char [] { ' ' }, StringSplitOptions.RemoveEmptyEntries));
//replace all constants with actual values
this.constant.SolveConstants(tokens);
//if there is only one token and it's a number
if (tokens.Count == 1 && this.core.IsNumber(tokens [0]))
{
//parse the number, it is the final answer
return(new CalcResult(this.core.Solve(tokens [0])));
}
int counter = 0;
while (tokens.Count > 0)
{
int nonNumberIndex = tokens.FindIndex(a => core.IsNumberWithNegative(a) == false);
//-1 means the only token is a number
if (nonNumberIndex == -1)
{
//parse the number, it is the final answer
return(new CalcResult(this.core.Solve(tokens [0])));
}
else
{
//if the token is negation
if (this.operatorr.IsNegation(tokens [nonNumberIndex]))
{
//solve it, remove the tokens from list, insert output in place
double result = this.operatorr.Solve(tokens [nonNumberIndex - 1], tokens [nonNumberIndex]);
tokens.RemoveRange(nonNumberIndex - 1, 2);
tokens.Insert(nonNumberIndex - 1, result.ToString());
}
else if (this.operatorr.IsToken(tokens [nonNumberIndex])) //if token is something other than negation
//solve it, remove the tokens from list, insert output in place
{
int i = nonNumberIndex;
//if first operator is out of bounds, then syntax error
if (i - 2 < 0)
{
return(new CalcResult(CalcError.SyntaxError));
}
double result = this.operatorr.Solve(tokens [i - 2], tokens [i - 1], tokens [i]);
tokens.RemoveRange(i - 2, 3);
tokens.Insert(i - 2, result.ToString());
}
else if (this.function.IsToken(tokens [nonNumberIndex])) //if token is a function
//if parameter is out of bounds, then syntax error
{
if (nonNumberIndex - 1 < 0)
{
return(new CalcResult(CalcError.SyntaxError));
}
//solve it, remove the tokens from list, insert output in place
double result = this.function.Solve(tokens [nonNumberIndex - 1], tokens [nonNumberIndex]);
tokens.RemoveRange(nonNumberIndex - 1, 2);
tokens.Insert(nonNumberIndex - 1, result.ToString());
}
}
counter++;
if (counter >= Calc.InfiniteLoopBreakingPoint)
{
return(new CalcResult(CalcError.InfiniteLoop));
}
}
return(new CalcResult(CalcError.Unknown));
}
