Character classes are supported like this: TRegexp re("[0-9]+")
But you are right that we should add more clear doc. For the time being
have a look at: http://root.cern.ch/lxr/source/base/src/Match.cxx
-- Fons
On Thu, 2002-08-08 at 00:36, Christian Holm Christensen wrote:
> Hi David,
>
> On Wed, 07 Aug 2002 14:50:30 CDT
> David Faden <dfaden@iastate.edu> wrote
> concerning "[ROOT] What features does TRegexp support?":
> > Hi,
> > What regular expression features does TRegexp have? The following
> > expression (taken from the perldata man page) doesn't seem to work:
> >
> > ^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$
>
> First off, you did remember to escape the backslashes, didn't you?
>
> Second off, it has previously been mentioned [1] that TRegexp does not
> support all Perl extensions to the `normal' (Posix?) regular
> expressions - I think Emacs Regular Expressions is a better reference
> (start emacs, type "C-h i m emacs C-j m Regexps C-j").
>
> Thirdly, I'm not sure about the underlined:
>
> ^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$
> ^^^
>
> What do you mean? Is it an optional '(' - in that case I think it
> needs to be escaped, otherwise you have a syntax error. Is it a Perl
> operator? - in that case, I don't think it's valid.
>
> However, I do agree that some doc on the avaliable operators, ladida,
> would be nice. For example, is character classes supported:
>
> root [0] TString n("1234")
> root [1] TRegexp re("[[:digit:]]+")
> root [2] int l
> root [3] re.Index(n, &l)
> (const Ssiz_t)(-1)
>
> Doesn't seem like it.
>
> There's a Perl compatible library called pcre (Perl Compatible Regular
> Expressions), avaliable for many platforms at [2]. If you're on a
> GNU/Linux box, chances are that you have it already. A C++ wrapper
> exists at [3] too. See also [4]
>
> Yours,
>
> ____ | Christian Holm Christensen
> |_| | -------------------------------------------------------------
> | | Address: Sankt Hansgade 23, 1. th. Phone: (+45) 35 35 96 91
> _| DK-2200 Copenhagen N Cell: (+45) 24 61 85 91
> _| Denmark Office: (+45) 353 25 305
> ____| Email: cholm@nbi.dk Web: www.nbi.dk/~cholm
> | |
>
>
>
> [1] http://root.cern.ch/root/roottalk/roottalk01/4536.html
> [2] http://www.pcre.org/
> [3] ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Contrib/
> [4] http://www.daemon.de/pcre++/
--
Org: CERN, European Laboratory for Particle Physics.
Mail: 1211 Geneve 23, Switzerland
E-Mail: Fons.Rademakers@cern.ch Phone: +41 22 7679248
WWW: http://root.cern.ch/~rdm/ Fax: +41 22 7679480
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