How would you organize such structure

[maksim1979]

Hey hey,

Guys, C++ is still a pain for me, so any advice would be really helpfull. Actually I have to parse a file that has a very simple format, namely it's just a list of records [record 1][...][record N], where each record has this structure:
[keyword; type; number of elements N; N elements of the specified type]. In other words such file could look like:
@["key1"; int; 3; {2,7,9}]["key2"; string; 2; {"hello", "world"}]["key3"; float; 1; {3.1415926}]@
Now I need a structure that represents such format (my parse method would return it).

So I thought that the parse should return QList<Record> and Record structure would look like:
@
template <typename T>
struct Record {
QString keyword;
QList<T> data;
}
@
or something like that. And here the way I use it
@QList<Record> records = MyParser::parse("/path/to/file")@

But my compiler said that it would be compile it :(

One of possible solutions is to add one method for each possible type as here:
@
struct Record {
QString keyword;
QString type;

QList<int> getIntData();   
QList<float> getFloatData();

...
QList<QString> getStringData();
}
@

In this approach, I first have to check type and after that use appropriate methos, but looks ugly.

@
QList<Record> records = MyParser::parse("/path/to/file");

foreach(record : records ) {
if (record.type == "int") {
QList<int> data = record.getIntData();
...
} else if (record.type == "float") {
QList<flaot> data = record.getFloatData();
...
} ...
}
@

So any thoughts?

Thanks a lot,
Maxim

[SGaist]

Hi,

You might be interested by QVariant to store/retrieve your data

Hope it helps

[maksim1979]

Yep SGaist, thanks a lot. I've already found this class. I just have one question. Is it usually safe to use it from performance point of you?

[SGaist]

The only answer is: you need to test it for your needs. AFAIK, there are no particular hit using this class

[maksim1979]

Thanks a lot SGaist
Maxim