XQuery - RegEx Pattern Matcher

[derstubbi at gmx.de]

> In XQuery think I would start by doing a replace() to replace
> semicolons-not-within-quotes by some other delimiter (e.g. a PUA
> character),
> and then do a tokenize() to split the string on this new delimiter.

That is what I try to do ;)

But, "...to replace semicolons-not-within-quotes..." needs Regex to find those, or not ?




> > -----Original Message-----
> > From: http://x-query.com/mailman/listinfo/talk [mailto:http://x-query.com/mailman/listinfo/talk] 
> > Sent: 19 June 2009 11:29
> > To: Michael Kay; http://x-query.com/mailman/listinfo/talk
> > Subject: Re: RE:  XQuery - RegEx Pattern Matcher
> > 
> > I am trying to "read" CSV data like this :
> > 
> > one;"two;stilltwo";three;"four;stillfour";five
> > 
> > this should resolve in something like this :
> > ...
> > <element>one</element>
> > <element>two;stilltwo</element>
> > <element>three</element>
> > <element>four;stillfour</element>
> > <element>five</element>
> > ...
> > 
> > if there is no separator(";") allowed within a text it is 
> > easy with just splitting a line with ";".
> > 
> > But if there can be a ";" as a text, than I have to use RegEx.
> > I succeded in finding a XQuery-RegEx if in one line there is 
> > only one case where a ";" is used as text.
> > 
> > But I need to find every match, so I used the \\G . Worked 
> > fine, so I hoped to reuse it in XQuery...
> > 
> > 
> > 
> > -------- Original-Nachricht --------
> > > Datum: Fri, 19 Jun 2009 10:20:30 +0100
> > > Von: "Michael Kay" <http://x-query.com/mailman/listinfo/talk>
> > > An: http://x-query.com/mailman/listinfo/talk, http://x-query.com/mailman/listinfo/talk
> > > Betreff: RE:  XQuery - RegEx Pattern Matcher
> > 
> > > 
> > > The XPath regular expression language does not recognize \G and it 
> > > does not recognize non-capturing groups.
> > > 
> > > As far as matches() is concerned, there is no distinction between 
> > > capturing and non-capturing groups, so replace "(?:" by "(".
> > > 
> > > I suspect you wanted your regex to contain "\G". In Java 
> > you need to 
> > > escape this as "\\G"; in XPath/XQuery, backslash is not a special 
> > > character and does not need to be escaped. However, there's 
> > no "\G" in 
> > > XPath regular expressions anyway. In Java it means "the end of the 
> > > previous match"; but XQuery is a functional language, so 
> > "previous" is 
> > > meaningless. At this stage I give up because I'm not sure 
> > what you are 
> > > trying to do: you haven't supplied enough of your code.
> > > 
> > > Regards,
> > > 
> > > Michael Kay
> > > http://www.saxonica.com/
> > > http://twitter.com/michaelhkay
> > > 
> > > > -----Original Message-----
> > > > From: http://x-query.com/mailman/listinfo/talk
> > > > [mailto:http://x-query.com/mailman/listinfo/talk] On Behalf Of http://x-query.com/mailman/listinfo/talk
> > > > Sent: 19 June 2009 09:33
> > > > To: http://x-query.com/mailman/listinfo/talk
> > > > Subject:  XQuery - RegEx Pattern Matcher
> > > > 
> > > > Hi,
> > > > I am trying to use a RegEx within XQuery. In general that 
> > works fine.
> > > > Now I have a more complex RegEx to work with CSV-files(these CSV 
> > > > have ";" as separator).
> > > > I use can the following without problems in Java :
> > > > 
> > > > Pattern Regex = Pattern.compile(
> > > > "\\G(?:^|;)(?:\"((?:[^\"]|\"\")*)\"|([^\";]*))");
> > > > ...
> > > > 
> > > > But in XQuery
> > > > let $regularExpr :='\\G(?:^|;)(?:\"((?:[^\"]|\"\")*)\"|([^\";]*))'
> > > > ...
> > > > if (matches($row,$regularExpr) ) then ( ...
> > > > 
> > > > just gives the error :
> > > > 
> > > > Error at character 4 in regular expression
> > > > "\\G(?:^|;)(?:\"((?:[^\"]|\"\")...": expected ())
> > > > 
> > > > 
> > > > I tried the optional flags (i, x, ...) but always with the same 
> > > > result...
> > > > What is wrong with this RegEx ?
> > > > 
> > > > P.S. :I run the XQuery from Java with Saxon.
> > > > 
> > > > 
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> > > > http://x-query.com/mailman/listinfo/talk
> > > 
> > > 
> > > _______________________________________________
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> > 
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