gistfile1.txt

token tryInt(std::string str)
{
    token result("INVALID", "");
    int state = 0;

    for(auto x : str)
    {
        switch(state)
        {
            case 0:
                if(x == '0')
                {
                    result.text.push_back(x);
                    state = 4;
                    result.type = "INT";
                }
                else if(x == '-')
                {
                    result.text.push_back(x);
                    state = 1;
                }
                else if(x >= '1' && x <= '9')
                {
                    result.text.push_back(x);
                    state = 2;
                    result.type = "INT";
                } else return result;
                break;
            case 1:
                if(x >= '1' && x <= '9')
                {
                    result.text.push_back(x);
                    state = 2;
                    result.type = "INT";
                } else return result;
                break;
            case 2:
                if(x >= '0' && x <= '9')
                {
                    result.text.push_back(x);
                }
                else if(x == 'l' || x == 'L')
                {
                    result.text.push_back(x);
                    result.type = "INT";
                    state = 3;
                }
                else
                {
                    result.type = "INVALID";
                    return result;
                }
        }
    }

    return result;
}