public StaticStack<MathOperation> Convert(string expression)
{
StaticStack<MathOperation> Output = new StaticStack<MathOperation>();
Stack<MathOperation> OperatorStack = new Stack<MathOperation>();
NumberState NumberState = NumberState.None;
float CommaMultiplier = 0;
float minus = 1;
bool useMinus = true;
for (int i = 0; i < expression.Length; i++)
{
char token = expression[i];
if (char.IsWhiteSpace(token))
{
//fixes 5 2 = 52
//new bug: 5 2 + = 7 (infix)
NumberState = NumberState.None;
continue;
}
if(token == '-')
{
if (useMinus)
{
minus = -1;
continue;
}
}
if (char.IsDigit(token))
{
float numeric = (float)char.GetNumericValue(token);
switch (NumberState)
{
case NumberState.None:
Output.Push((Number)(numeric * minus));
NumberState = NumberState.Number;
break;
case NumberState.Number:
float num = (Number)Output.PopReal();
Output.Push((Number)(num * 10.0 + numeric * NonNullSign(num)));
break;
case NumberState.Comma:
float num2 = (Number)Output.PopReal();
Output.Push((Number)(num2 + numeric * CommaMultiplier * NonNullSign(num2)));
CommaMultiplier *= 0.1f;
break;
default:
throw new NotImplementedException();
}
minus = 1;
useMinus = false;
}
else if (token == '.')
{
minus = 1;
NumberState = NumberState.Comma;
CommaMultiplier = 0.1f;
}
else if (token == ',')
{
NumberState = NumberState.None;
if (OperatorStack.Count == 0)
throw new MismatchedParenthesisException("\"" + expression.Substring(i) + "\": Can't find opening parenthesis");
while (OperatorStack.Count > 0)
{
if (OperatorStack.Peek() is Parenthesis)
break;
Output.Push(OperatorStack.Pop());
}
if (OperatorStack.Count == 0 || !(OperatorStack.Peek() is Parenthesis))
throw new MismatchedParenthesisException("\"" + expression.Substring(i) + "\": Can't find opening parenthesis");
}
else if (token == ')')
{
if (OperatorStack.Count == 0)
throw new MismatchedParenthesisException("\"" + expression.Substring(i) + "\": Can't find opening parenthesis");
while (OperatorStack.Count > 0)
{
MathOperation TopOperator = OperatorStack.Pop();
if (TopOperator is Parenthesis)
break;
else
Output.Push(TopOperator);
if (OperatorStack.Count == 0)
throw new MismatchedParenthesisException("\"" + expression.Substring(i) + "\": Can't find opening parenthesis");
}
if (OperatorStack.Count > 0 && OperatorStack.Peek() is Function)
Output.Push(OperatorStack.Pop());
useMinus = false;
}
else if (char.IsSymbol(token) || char.IsPunctuation(token))
{
string fullname = "";
for (; i < expression.Length; i++)
{
char letter = expression[i];
if ((char.IsSymbol(letter) || char.IsPunctuation(letter)))
//we cant use letters or 5 + sin(x) is going to break
fullname += char.ToLower(letter);
else
{
--i;
break;
}
if (m_Operators.ContainsKey(fullname))
break;
}
if (m_Operators.ContainsKey(fullname))
{
MathOperation TokenOperator = m_Operators[fullname];
if (NumberState != MathState.NumberState.None)
{
NumberState = NumberState.None;
if (TokenOperator is Parenthesis)
{
// makes 5(x) possible
OperatorStack.Push(new MathOperations.Operators.Multiplication());
}
}
while (OperatorStack.Count > 0)
{
MathOperation TopOperator = OperatorStack.Peek();
if (TokenOperator.Association == Association.Left && TokenOperator.Precedence <= TopOperator.Precedence)
Output.Push(OperatorStack.Pop());
else if (TokenOperator.Association == Association.Right && TokenOperator.Precedence < TopOperator.Precedence)
Output.Push(OperatorStack.Pop());
else
break;
}
OperatorStack.Push(TokenOperator);
}
useMinus = true;
}
else if (char.IsLetter(token))
{
minus = 1;
string fullname = "";
for (; i < expression.Length; i++)
{
char letter = expression[i];
if (char.IsLetter(letter))
fullname += char.ToLower(letter);
else
{
--i;
break;
}
}
if (NumberState != MathState.NumberState.None)
{
NumberState = NumberState.None;
OperatorStack.Push(new MathOperations.Operators.Multiplication());
}
if (m_Functions.ContainsKey(fullname))
OperatorStack.Push(m_Functions[fullname]);
else if (m_Variables.ContainsKey(fullname))
{
Output.Push(new Variable(fullname, m_Variables));
}
else if (m_Constants.ContainsKey(fullname))
{
Output.Push(new Constant(fullname, m_Constants[fullname]));
}
else if (DefineUnknownVariables)
Output.Push(new Variable(fullname,m_Variables));
else
throw new UndefinedFunctionException("Function \"" + fullname + "\" not defined");
useMinus = false;
}
else
{
throw new NotSupportedException();
}
}
while (OperatorStack.Count > 0)
{
if (OperatorStack.Peek() is Parenthesis)
throw new MismatchedParenthesisException("Can't find closing parenthesis");
Output.Push(OperatorStack.Pop());
}
return Output;
}