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++/
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