expression.cpp

#include <iostream>

#include "expression.h"

Expression::Expression()
{
    saPile = new std::stack<int>();
}


Expression::~Expression()
{
    delete saPile;
}


int Expression::evaluer(std::vector<char>* unTab)
{
    while (!saPile->empty())
    {
        saPile->pop();
    }

    for (std::vector<char>::iterator it = unTab->begin(); it != unTab->end(); it++)
    {
        if ((*it) >= '0' && (*it) <= '9')
        {
            saPile->push(conversionCharEnInt(*it));
            //std::cout << "Empile: " << saPile->top() << std::endl;
        }
        else
        {
            saPile->push(traiterOperation(*it));
            //std::cout << "Empile: " << saPile->top() << std::endl;
        }
    }

    if (saPile->size() > 1) throw 3;
    return saPile->top();
}


int Expression::conversionCharEnInt(char unChar)
{
    return unChar - '0';
}


int Expression::traiterOperation(char uneOp)
{
    int a, b;

    if (saPile->empty()) throw(2);
    b = saPile->top();
    saPile->pop();
    //std::cout << "Dépile: " << b << std::endl;

    if (saPile->empty()) throw(2);
    a = saPile->top();
    saPile->pop();
    //std::cout << "Dépile: " << a << std::endl;

    switch (uneOp)
    {
    case '+':
        return a+b;
        break;
    case '-':
        return a-b;
        break;
    case '*':
        return a*b;
        break;
    case '/':
        if (b == 0) throw 0;
        return a/b;
        break;
    case '%':
        if (b == 0) throw 0;
        return a%b;
        break;
    case '<':
        return a<b;
        break;
    case '>':
        return a>b;
        break;
    case '=':
        return a==b;
        break;
    case '!':
        return a!=b;
        break;
    case '&':
        return a&&b;
        break;
    case '|':
        return a||b;
        break;
    }

    throw 1;
    return 0;
}