id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
3513	regex_match very slow example	Fernando Pelliccioni <fpelliccioni@…>	Eric Niebler	"Hi, 

I am having an issue with a dynamic regular expresion.

I have this source code.

sregex tempRE = sregex::compile(""^(?:.*\\r?\\n)*var wlanPara = new Array\\(\\r?\\n\\d{0,4},\\r?\\n\""(?P<ssid>(?:\\w+))\"",\\r?\\n(?P<channel>(?:\\d{0,4})),\\r?\\n\\d{0,4},\\r?\\n\""[\\w-]+\"",\\r?\\n\""[\\w\\.]+\"",\\r?\\n\\d{0,4},\\r?\\n\\d{0,4},\\r?\\n\""(?P<signal>(?:\\d{0,4})) dB\"",\\r?\\n\\d{0,4},\\d{0,4} \\);(?:.*\\r?\\n)*$"");

std::string htmlText; // filled using text in html file attached


smatch what;

if(regex_match(htmlText, what, tempRE))
{
	//...
}

When the program enters to the regex_match function, the process consumes 50% of the processor and the function never returns.

I was attach the html file that contains the text.
The source code was tested using VisualStudio 2008.


If I use the static variant of regex, it's works perfectly..

sregex tempRE = bos >> *_ >> ""var wlanPara = new Array("" >> _ln >> _d >> commonDigit >> ',' >> _ln >> '""' >> (s1= +_w) >> ""\"","" >> _ln >> (s2= commonDigit) >> ',' >> _ln >> commonDigit >> ',' >> _ln >> '""' >> +(_w | '-') >> ""\"","" >> _ln >> '""' >> +(_w | '.') >> ""\"","" >> _ln >> commonDigit >> ',' >> _ln >> commonDigit >> ',' >> _ln >> '""' >> (s3= commonDigit) >> "" dB\"","" >> _ln >> commonDigit >> ',' >> commonDigit >> "" );"" >> *_ >> eos;



Thanks,

Fernando Pelliccioni"	Support Requests	closed	Boost 1.41.0	xpressive	Boost 1.40.0	Problem	invalid