Russian Qt Forum

#ifndef MATHEXPRESSIONPARSER_H
#define MATHEXPRESSIONPARSER_H

#include<string>
#include <iostream>
#include <sstream>
#include<vector>


using namespace std;

namespace MMCalculator{
    enum TokenType
    {
        OPERAND = 0,
        OPERATOR = 2
    };

    enum OperatorType
    {
        ADDITION = 0,
        SUBTRACTION = 1,
        MULTIPLICATION = 2,
        DIVISION = 3
    };

    class OutputUnit
    {
    public:
        virtual TokenType getTokenType() = 0;
    };

    class Operand : OutputUnit
    {
    private:
        double value;
    public:
        Operand(double value);
        double getValue();
        TokenType getTokenType();
    };

    class Operator : OutputUnit
    {
    private:
        OperatorType operatorType;
    public:
        Operator(OperatorType operatorType);
        OperatorType getOperatorType();
        TokenType getTokenType();
    };

    class MathExpressionParser
    {
    private:
        std::istream* inputStream;
        std::vector<OutputUnit> outputUnits;
        std::vector<Operator> stack;
        void procDigit();
    public:
        double parseExpression(std::string expression);
    };
}

#endif // MATHEXPRESSIONPARSER_H