Subject: Re: [Boost-bugs] [Boost C++ Libraries] #4309: Negative lookbehind assertion error
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2010-06-08 10:20:23
#4309: Negative lookbehind assertion error
--------------------------+-------------------------------------------------
Reporter: anonymous | Owner: johnmaddock
Type: Bugs | Status: new
Milestone: Boost 1.43.0 | Component: regex
Version: Boost 1.43.0 | Severity: Problem
Keywords: |
--------------------------+-------------------------------------------------
Comment(by anonymous):
I wouldn't be too sure.
(?<!pattern)
A zero-width negative look-behind assertion. For example /(?<!bar)foo/
matches any occurrence of "foo" that does not follow "bar". '''Works only
for fixed-width look-behind'''.
Both foo and bar are fixed-width, so ORing them should also be fixed
width. There is no quantifier used in the sample.
For comparison, in .NET, System.Text.RegularExpressions.Regex does it
'right'. The .NET regular expression engine is designed to be mostly
compatible with Perl 5 regular expressions. Hmmm?
-- Ticket URL: <https://svn.boost.org/trac/boost/ticket/4309#comment:2> Boost C++ Libraries <http://www.boost.org/> Boost provides free peer-reviewed portable C++ source libraries.
This archive was generated by hypermail 2.1.7 : 2017-02-16 18:50:03 UTC