How to parse content of a file and load into the map - c++

Question

i want to parse the content of a file and load into a map.
This is the file content format:
Movie-name release-year price cast ishd
"DDLG" 2010 20.00 "shahrukh and Kajal" true
"Aamir" 2008 10.00 "abc, xyz and ijkl" false
Key for map will be the first word (Movie name).
class defition:
class movieInfo
{
private:
int releaseYear;
double price;
string cast;
bool isHD;
};
This is the function i am trying to implement.
void fill_map_contents (map <string, movieInfo*> &mymap, ifstream& myfile)
{
string line;
string word;
while (getline(myfile, line))
{
out << "inside while loop " << line << endl;
stringstream tokenizer;
tokenizer << line;
movieInfo *temp = new movieInfo;
while (tokenizer >> word)
{
cout << " printing word :->"<< word << endl;
//temp->releaseYear = atoi(word);
//temp->price = 12.34;
//temp->cast = "sahahrukh salman";
//temp->isHD = false;
mymap[word] = temp;
}
delete temp;
}
}
I am not getting any idea, after while (tokenizer >> word), how to fill object variable and assign it to map.
Any help will be highly appreciated.
Devesh

Answer 1

cout << " printing word :->"<< word << endl;
//temp->releaseYear = atoi(word);
//temp->price = 12.34;
//temp->cast = "sahahrukh salman";
//temp->isHD = false;
in above code you are trying to access private members of the class directly which is not possible.Hence ,better solution is you should include public getter/setter for each variable as follows.
public:
void setreleaseYear(int sry){releaseYear=sry;}
void setprice(double pr){price=pr;}
void setcast(string cast){string=str;}
void setisHD(bool id){isHD=id;}
now use in place of commented code :
//temp->releaseYear = atoi(word);
temp->setreleaseYear(atoi(word));
tokenizer >> word;
//temp->price = 12.34;
temp->setprice(atof(word));
tokenizer >> word;
//temp->cast = "sahahrukh salman";
temp->setcast(word);
tokenizer >> word;
//temp->isHD = false;
temp->setisHD(word);
No need of while loop.

Answer 2

You must simplify things. I suggest to add inserction and extraction operator for movieinfo and choose new line as field separator
DDLG
2010
20.00
shahrukh and Kajal
true
Aamir
2008
10.00
abc, xyz and ijkl
false
class movieInfo
{
public:
int releaseYear;
double price;
string cast;
bool isHD;
friend std::ostream& operator << ( std::ostream& os, const movieinfo& i )
{
return os << i.releaseYear << '\n'
<< i.price << '\n'
<< i.cast << '\n'
<< std::boolalpha << i.isHD() << '\n';
}
friend std::istream& operator >> ( std::istream& is, movieinfo& i )
{
is >> i.releaseYear
>> i.price;
getline( is, i.cast );
return is >> std::boolalpha >> i.isHD;
}
};
void fill_map_contents (map <string, movieInfo> &mymap, ifstream& myfile)
{
while ( !myfile.eof )
{
string name;
myfile >> name;
movieInfo mi;
myfile >> m1;
mymap[ name ] = movieInfo;
}
}
note that I changed map <string, movieInfo*> in map <string, movieInfo> prefer using move semantic.
Another suggestion I will change moveinfo in:
class movieInfo
{
public:
// ctor and move, assign operator and move operator
int releaseYear() const { return mReleaseYear; };
double price() const { return mPrice; };
const string& cast() const { return mCast; };
bool isHD() const { return mIsHD; };
private:
int mReleaseYear;
double mPrice;
string mCast;
bool mIsHD;
friend std::ostream& operator << ( std::ostream& os, const movieinfo& i )
{
return os << i.releaseYear() << '\n'
<< i.price() << '\n'
<< i.cast() << '\n'
<< std::boolalpha << i.isHD() << '\n';
}
friend std::istream& operator >> ( std::istream& is, movieinfo& i )
{
is >> i.mReleaseYear
>> i.mPrice;
getline( is, i.mCast );
return is >> i.mIsHD;
}
};

Answer 3

You are effectively trying to parse a CSV file, with space as separator and " as quote character.
I'd recommend using a library for this, like this one.
Example code (taken from the help page):
// Note: I changed mymap to map<string, movieInfo> without a pointer - it's not
// needed
const char field_terminator = ' '; // Use a space
const char line_terminator = '\n'; // Use line break
const char enclosure_char = '"'; // Use "
csv_parser file_parser;
file_parser.set_skip_lines(1);
file_parser.init(filename);
file_parser.set_enclosed_char(enclosure_char, ENCLOSURE_OPTIONAL);
file_parser.set_field_term_char(field_terminator);
file_parser.set_line_term_char(line_terminator);
while(file_parser.has_more_rows()) {
csv_row row = file_parser.get_row();
movieInfo temp; // No need for pointers
temp->releaseYear = atoi(row[1]); // C++11: Use std::stoi()
temp->price = atof(row[2]); // C++11: Use std::stof()
temp->cast = row[3];
temp->isHD = row[4].compare("true") == 0;
mymap[row[0]] = temp;
}