//---------------------------------------------------------
// Lab08Graphics.cpp
//
//
// D. Searls
// Asbury College
// 2008
//---------------------------------------------------------
#include <iostream>
#include <iomanip>
#include <fstream>
#include <sstream>
#include "list.cpp"
#include "stack.cpp"
#include <cmath>

using namespace std;

struct tokenType
{
    bool isOperand;
    double operand;
    string op;
};

//-----------------------------------------------
// precedence
//
// Returns the precedence of the specified
// operator based on this table:
//
// Operator  Precedence
// --------  ----------
// function      4
//     ^         3
//     *         2
//     /         2
//     +         1
//     -         1
//     (         0
//     ""        0  Null Operator
//
// Precondition: the operator is "+", "-", "*",
// "/", "^", "(", "" or a function.
//
// In Parameter: op
//-----------------------------------------------
int precedence(string op)
{
}

//-----------------------------------------------
// Function: convertToPostfix
//
// Convert the infix expression (read from the
// specified string stream) into a postfix
// expression.
//
// Precondition: the infix expression consists of
// space-delimited tokens and has no errors.
//
// In Parameter: infix
// Out Parameter: postfix
//-----------------------------------------------
void convertToPostfix(stringstream& infix, list<tokenType>& postfix)
{
}

//---------------------------------------------------------
// valueOf
//
// Given the value of the independent variable, x, this
// function returns the value of the postfix expression.
//
// In Parameters: postfix, x
//---------------------------------------------------------
double valueOf(list<tokenType>& postfix, double x)
{
}

//*********************************************************
//                   M A I N   D R I V E R
//*********************************************************

int main()
{
    list<tokenType> postfix;
    tokenType* ptr;
    string infix;
    stringstream infixStream;
    double x;
    
    cout << "Given an infix expression, this application will\n";
    cout << "display the corresponding postfix expression and\n";
    cout << "its value.\n\n";
    cout << "To terminate, just tap the Enter key when asked\n";
    cout << "for an infix expression.\n\n";
    
    cout << "  Infix: ";
    getline(cin, infix);
    while (infix.length() > 0)
    {
        cout << "      x: ";
        cin >> x;
        cin.ignore();
        infixStream.str(infix);
        postfix.clear();
        convertToPostfix(infixStream, postfix);
        infixStream.clear();

        cout << "Postfix: ";

        for (ptr = postfix.first(); ptr != postfix.end(); ptr = postfix.next())
        {
            if (ptr->isOperand)
            {
                if (isnan(ptr->operand))
                {
                    cout << x;
                }
                else
                {
                    cout << ptr->operand;
                }
            }
            else
            {
                cout << ptr->op;
            }
            cout << ' ';
        }
        cout << " = " << valueOf(postfix, x) << endl << endl;
        
        cout << "  Infix: ";
        getline(cin, infix);
    }
    
    return 0;
}