Qt regex modifier

yodusow bardon

I'm trying to use a regex that uses \u modifier:

(?:\\.(?:[a-z\\u00a1-\\uffff]{2,}))

It would match strings like .com, the tld of an url, but when I call isValid() it returns false and when running I got this warning:

QRegularExpressionPrivate::doMatch(): called on an invalid QRegularExpression object

Is there a solution? What can I be doing in order to solve this?

mrjj

@yodusow-bardon said:

Hi
I wonder if
QRegularExpression::UseUnicodePropertiesOption 0x0040
http://doc.qt.io/qt-5/qregularexpression.html
is what you are after?

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@mrjj I tried it too and it doesn't work. I my case I tried - it would match anything, including unicode characters:

[a-z\u00a1-\uffff0-9]*

And when calling isValid it returns false along with the same warning, even using UseUnicodePropertiesOption.

mrjj

@Minupi said:
hmm looking in
qregularexpression.cpp
I only see
QT_TRANSLATE_NOOP("QRegularExpression", "PCRE does not support \L, \l, \N{name}, \U, or \u"),

but at same time docs says "It fully supports Unicode"

Does it work if u put the unicode directly in the string ?

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@mrjj I might, but the thing is that I need to use \u as it has a range: \uffff0-9.

I think that I'm going to drop the QRegularExpression and use QRegExp instead.

mrjj

@Minupi said:
Well if it just accepts a \u I agree it seems more sensible than to figure out how to do \u like with QRegularExpression.

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@mrjj It's kinda nonsense as QRegularExpresion came to be better than QRegExp, but anyway, let's stick with it as it's the only option left here.

Thank you.

mrjj

@yodusow-bardon said:
btw
did u try
\x{FFFF}

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@mrjj Yes, I did and I got an error saying:

hex constants must have at least one hex digit

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@mrjj I fixed it, and it's working now... You just have to escape the \x, like \\x, for instance: [a-z\\x{00a1}-\\x{ffff}0-9]*.

mrjj

@Minupi
Oh yes always escape "\"
Super- :)

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@mrjj Thank you, helped a lot. I realised that QRegularExpression is using the same syntax as PHP.

mrjj

@Minupi
Good to hear. :)
It says its perl syntax but maybe PHP uses perl style or reverse?

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@mrjj Yes, it resembles perl style, it's called PCRE.

SGaist

Hi,

To help you with your regular expression development, you can use the regular expression tool. It's available starting with Qt 5.6