COMPILATEUR BF VERS BF-BYTECODE

#include <iostream>
#include <fstream>
#include <string>

using namespace std;

void preprocess(fstream&, fstream&);
void compile(fstream&, fstream&);
void decompile(fstream&, fstream&);

int translate(char);
char untranslate(int);

int main(int argn, char** argv)
{
    if (argn != 4)
    {
        cout << "bar <input> <option> <output>" << endl;

        return 1;
    }

    fstream in(argv[1], ios::in);

    if (!in)
    {
        cout << argv[1] << ": no such file or directory" << endl;

        return 2;
    }

    fstream out(argv[3], (ios::out | ios::trunc));

    if (string(argv[2]) == "-c")
    {
        string tmpfile = (string(argv[1]) + ".bfp");

        fstream tmp(tmpfile.c_str(), ios::out | ios::trunc);

        preprocess(in, tmp);

        tmp.close();

        tmp.open(tmpfile.c_str(), ios::in);

        compile(tmp, out);

        tmp.close();

        remove(tmpfile.c_str());
    }

    if (string(argv[2]) == "-d")
        decompile(in, out);
    if (string(argv[2]) == "-e")
        preprocess(in, out);

    in.close();
    out.close();
}

int translate(char c)
{
    switch (c)
    {
        case '\0': return 0;
        case '>': return 1;
        case '<': return 2;
        case '+': return 3;
        case '-': return 4;
        case '{': return 5;
        case '}': return 6;
        case '.': return 7;
        case '?': return 8;
    }

    return 0;
}

char untranslate(int i)
{
    switch (i)
    {
        case 1: return '>';
        case 2: return '<';
        case 3: return '+';
        case 4: return '-';
        case 5: return '{';
        case 6: return '}';
        case 7: return '.';
        case 8: return '?';

        default: return '\0';
    }
}

void preprocess(fstream& in, fstream& out)
{
    string buffer = "";
    char c = 0;

    while (in >> c)
    {
        if (c == '#')
            getline(in, buffer);

        if ((c == '>') or (c == '<') or (c == '+') or (c == '-')
        or (c == '{') or (c == '}') or (c == '?') or (c == '.'))
            out << c;

        if (c == ',')
            out << '?';
        if (c == '[')
            out << '{';
        if (c == ']')
            out << '}';
    }
}

void compile(fstream& in, fstream& out)
{
    uchar c = 0;
    uchar c2 = 0;

    int i = 0;

    while (in >> c >> c2)
    {
        out << (char)((16 * translate(c)) + translate(c2));
        i++;
    }

    if ((i % 2) == 0)
    {
        in >> c;

        out << (char)((16 * translate(c)) + 0);
    }
}

void decompile(fstream& in, fstream& out)
{
    int i = 0;
    int j = 0;

    char c = 0;

    while (in >> c)
    {
        i = (((uchar)c) / 16);
        j = (((uchar)c) % 16);

        out << untranslate(i) << untranslate(j);
    }
}