One small note, you are wasting CPU cycle here. The QRegularExpressionMatchIterator returns only match objects that contains a match thus the if is useless.

Sure, they are in the docs: http://doc.qt.io/qt-5/qregexp.html#code-examples indexIn() method should interest you in this case.

QRegularExpression rx("[A-Za-z0-9]*"); QRegularExpressionalidator *v = new QRegularExpressionValidator(rx, this); ui->LE_ObjectName->setValidator(v);

@MarkoSan said: are there any solutions for current code? either you enclose the RegExp pattern in tr() and trust the translator to do the right thing or you declare private: const QString logTags[3]; then in the constructor add the initialisation UeLogWindow::UeLogWindow(QWidget parent) : \\ ... other inits , logTags{tr("[INFO]"),tr("[WARNING]"),tr("[ERROR]")} (if you don't have access to C++11 functionality you should not declare const and initialise the members with the usual [] operator) this also simplifies a lot the switch(logEntryType) part to use them in the regular expression you then just have to call QRegularExpression::escape(). for example, ruleError.pattern=QRegExp("^\[ERROR\].*"); would become ruleError.pattern=QRegExp("^"+QRegExp::escape(logEntryType[2])+".*"); Again, here I used QRegExp but you should REALLY use QRegularExpression especially if you expect a big number of matches

not the same (.*?) and (.*) I tested on QT4 and QT5 Ok I found the solution with this regular expression: QRegExp regex("\\<date(:(.*))?\\>");

Reading that report and thinking about it it makes sense that it is not an actual bug. For [a-z] it should not be escaped, since you want to match all characters from a up to character z. For [a\-z] you want to match character a, or character hyphen or character z.

What OS and Qt version are you using? On windows the end-of-line (EOL) marking is done by \r\n, although I'm not sure how it is done in the QPlainTextEdit class, but it may worth to give a try. IIRC QRegExp should be replaced QRegularExpression in recent code, but I don't think this is the problem. And I'm not sure about the regex you posted: the caret should negate the content of the class, therefore matching any character not being a number or a spacing, resulting in exactly the opposite. If you basically basically want to reject any string containing a letter, then you could try to reverse your regex to "[^a-z,A-z]+".

You're welcome ! Sure thing Happy coding !

You are probably right. I have added a report on JIRA