expression.cpp +float

#include <iostream>
#include <cmath>

#include "expression.h"

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


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


double Expression::chiffresEnNombre(std::vector<int>* unTab)
{
    unsigned int i, j=unTab->size();
    double n=0.;

    for (i=0; i < unTab->size(); i++)
    {
        if ((*unTab)[i] < 0)
        {
            if (j < unTab->size()) throw 4;

            j = i;
        }
    }

    for (i=0; i < unTab->size(); i++)
    {
        if (i == j) continue;

        n += (*unTab)[i] * pow(10., (int)j - (int)i - (i < j));
    }

    return n;
}


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

    std::vector<int>* leTabChiffres = new std::vector<int>();

    for (std::vector<char>::iterator it = unTab->begin(); it != unTab->end(); it++)
    {
        if (((*it) >= '0' && (*it) <= '9') || (*it) == '.')
        {
            leTabChiffres->push_back(conversionCharEnInt((*it) == '.' ? -1 : (*it)));
        }
        else
        {
            if (!leTabChiffres->empty())
            {
                saPile->push(chiffresEnNombre(leTabChiffres));
                //std::cout << "Empile: " << saPile->top() << std::endl;
                leTabChiffres->resize(0);
            }

            switch (*it)
            {
            case ' ':
                continue;
            default:
                saPile->push(traiterOperation(*it));
                //std::cout << "Empile: " << saPile->top() << std::endl;
                break;
            }
        }
    }

    if (!leTabChiffres->empty())
    {
        saPile->push(chiffresEnNombre(leTabChiffres));
    }
    delete leTabChiffres;

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


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


double Expression::traiterOperation(char uneOp)
{
    double 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;
    case '-':
        return a-b;
    case '*':
        return a*b;
    case '/':
        if (b == 0.) throw 0;
        return a/b;
    case '<':
        return a<b;
    case '>':
        return a>b;
    case '=':
        return a==b;
    case '!':
        return a!=b;
    case '&':
        return a&&b;
    case '|':
        return a||b;
    }

    throw 1;
    return 0.;
}

// EOF