C++14
Generally, the staff in university has recommended us to use Boost to parse the file, but I've installed it and not succeeded to implement anything with it.
So I have to parse a CSV file line-by-line, where each line is of 2 columns, separated of course by a comma. Each of these two columns is a digit. I have to take the integral value of these two digits and use them to construct my Fractal objects at the end.
The first problem is: The file can look like for example so:
1,1
<HERE WE HAVE A NEWLINE>
<HERE WE HAVE A NEWLINE>
This format of file is okay. But my solution outputs "Invalid input" for that one, where the correct solution is supposed to print only once the respective fractal - 1,1.
The second problem is: The file can look like:
1,1
<HERE WE HAVE A NEWLINE>
1,1
This is supposed to be an invalid input but my solution treats it like a correct one - and just skips over the middle NEWLINE.
Maybe you can guide me how to fix these issues, it would really help me as I'm struggling with this exercise for 3 days from morning to evening.
This is my current parser:
#include <iostream>
#include "Fractal.h"
#include <fstream>
#include <stack>
#include <sstream>
const char *usgErr = "Usage: FractalDrawer <file path>\n";
const char *invalidErr = "Invalid input\n";
const char *VALIDEXT = "csv";
const char EXTDOT = '.';
const char COMMA = ',';
const char MINTYPE = 1;
const char MAXTYPE = 3;
const int MINDIM = 1;
const int MAXDIM = 6;
const int NUBEROFARGS = 2;
int main(int argc, char *argv[])
{
if (argc != NUBEROFARGS)
{
std::cerr << usgErr;
std::exit(EXIT_FAILURE);
}
std::stack<Fractal *> resToPrint;
std::string filepath = argv[1]; // Can be a relative/absolute path
if (filepath.substr(filepath.find_last_of(EXTDOT) + 1) != VALIDEXT)
{
std::cerr << invalidErr;
exit(EXIT_FAILURE);
}
std::stringstream ss; // Treat it as a buffer to parse each line
std::string s; // Use it with 'ss' to convert char digit to int
std::ifstream myFile; // Declare on a pointer to file
myFile.open(filepath); // Open CSV file
if (!myFile) // If failed to open the file
{
std::cerr << invalidErr;
exit(EXIT_FAILURE);
}
int type = 0;
int dim = 0;
while (myFile.peek() != EOF)
{
getline(myFile, s, COMMA); // Read to comma - the kind of fractal, store it in s
ss << s << WHITESPACE; // Save the number in ss delimited by ' ' to be able to perform the double assignment
s.clear(); // We don't want to save this number in s anymore as we won't it to be assigned somewhere else
getline(myFile, s, NEWLINE); // Read to NEWLINE - the dim of the fractal
ss << s;
ss >> type >> dim; // Double assignment
s.clear(); // We don't want to save this number in s anymore as we won't it to be assigned somewhere else
if (ss.peek() != EOF || type < MINTYPE || type > MAXTYPE || dim < MINDIM || dim > MAXDIM)
{
std::cerr << invalidErr;
std::exit(EXIT_FAILURE);
}
resToPrint.push(FractalFactory::factoryMethod(type, dim));
ss.clear(); // Clear the buffer to update new values of the next line at the next iteration
}
while (!resToPrint.empty())
{
std::cout << *(resToPrint.top()) << std::endl;
resToPrint.pop();
}
myFile.close();
return 0;
}
