Getting an index of match using QRegExp.

piotrekd

Hello, when I tried to write an simple module to remove multi-line comments from cpp file I've got a problem with getting an index of begin and end of comment section.

I merged the whole of file into one QString called "text" in code below.
@
QRegExp rx = QRegExp("\/\"); // matches begin of comment section
QRegExp rx2 = QRegExp("\\/"); // matches end of comment section

qDebug() << rx.indexIn(this->text); // returns corrrectly one, first index but I need all of them so I think I need to use code below
qDebug() << rx.pos(1);          // returns -1 so It didn't match
qDebug() << rx.pos(2);        // same here

@

Sample output:
@

Starting /home/piotrek/dev/qt/scs_finder-build-desktop/scs_finder...

"#include <boost/lambda/lambda.hpp> /* Sample / #include <iostream> #include <iterator> #include <algorithm> int main() { using namespace boost::lambda; typedef std::istream_iterator<int> in; / Annother sample */ std::for_each( in(std::cin), in(), std::cout << (_1 * 3) << " " ); } "

35
-1
-1
@

I'll be very happy if someone could give me a tip how to resolve this problem.
Greetings,
Piotrek

Richard Neal

Since your using QString, something like this maybe?

@#include <QtCore/QRegExp>
#include <QtCore/QDebug>

int main()
{
QString s1 = "1: Some code commented /* this is a comment / more code";
//QString s1 = "1: Some code commented / this is a comment more code";

int start = s1.indexOf( "/*" );
int end = s1.indexOf( "*/" );

if( end > start ){
    QString tmpStr;
    for( int i = start; i <= end+1; ++i ){
        tmpStr.append( s1[i] );
    }
    qDebug() << tmpStr;
} else {
    qDebug() << "Invalid comment found:\n\t" << s1;
}

}@

dangelog

[quote author="Richard Neal" date="1314968851"]
@
QString tmpStr;
for( int i = start; i <= end+1; ++i ){
tmpStr.append( s1[i] );
}
@
[/quote]

QString::mid().

Richard Neal

Sure - (would need to calculate length you want from pos in that case).

Like:
@#include <QtCore/QRegExp>
#include <QtCore/QDebug>

int main()
{
QString s1 = "1: Some code commented /* this is a comment / more code";
//QString s1 = "1: Some code commented / this is a comment more code";

int start = s1.indexOf( "/*" );
int end = s1.indexOf( "*/" );

if( end > start ){
    qDebug() << s1.mid( start, end-start+2 );
} else {
    qDebug() << "Invalid comment found:\n\t" << s1;
}

}@

piotrekd

Thanks for all replies, that is what I needed :)