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Re: [Boost-users] regex iterator question
by Mike Marchywka 30 Mar '09

30 Mar '09

---------------------------------------- > To: boost-users(a)lists.boost.org > Date: Mon, 30 Mar 2009 12:48:48 -0400 > From: dfs(a)savarese.org > Subject: Re: [Boost-users] regex iterator question > > > In message , "Robert Ramey" writes: >>Thinking about it, this problem must come very often. How is it usually >>addressed? There must be a simple bridge across this. In a pinch, I'll >>just have to load the whole file into some sort collection, but I prefer the >>ultimate unlimited file size solution. > I always like unbounded solutions too but if you try to stream a file past a regex-er it is likely to be slow, and as pointed out by others, not even reasonable in the general case although you may want to think about specialized cases that may benefit from any restricted set of regex'es you have. You would have to think about "strategies" or similar notions that look at the problem and pick an approach or specific implementation based on parameters. I originally came here to do 1000's of REGEX queries on megabyte strings and ultimately used Boost and Greta for testing but quickly found ways to compile query/sample vectors and implement restricted searches once I found all the not-so-regular expressions fit a given constraint or could even do simple things like sorts to preserve locality later. There are a lot of potential performance limitations depending on the specific task parameters and machine. But, yes, it would be nice if someone had a general "strategy" library. LOL. > In the worst case, if you're using Perl-style expressions (or any style > that isn't strictly "regular" and requires backtracking; lookahead > assertions are a common culprit), the entire input may have to be > consumed and buffered even if the expression ultimately matches only a > few characters (see "On the Use of Regular Expressions for Searching Text", > Clark and Cormack, ACM Transactions on Programming Languages and Systems, > Vol 19, No. 3, pp 413-426.). Therefore, if you're dealing with small > files, you may as well buffer the entire file in a char array and use > regex_token_iterator. If you're dealing with large files, > memory map the file instead. > > daniel > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users _________________________________________________________________ Internet Explorer 8 – Get your Hotmail Accelerated. Download free! http://clk.atdmt.com/MRT/go/141323790/direct/01/

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Re: [Boost-users] Using boost regex dll in code
by John Maddock 30 Mar '09

30 Mar '09

> Is there a way to contact you directly? I believe my confusion can be > solved rather quickly w/o using the user groups. You can use the john - at - johnmaddock.co.uk address to mail me directly, but I'll be offline for the day very shortly, Regards, John.

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regex iterator question
by Robert Ramey 30 Mar '09

30 Mar '09

I've got a need for regex and I would like to use it to extract tokens matching a regular expresssion from a file stream. Seems like this would be a common desire. So first shot is boost::regex_token_iterator<some_input_iterator> This doesn't work since regex_token_iterator requires a bidirectional iterator. Seems reasonable enough. So next I comb through boost and find #include <boost/spirit/iterator/multi_pass.hpp> and try boost::regex_token_iterator< boost::spirit::multi_pass<some_input_iterator> > I'm thinking this is veeeeeery cool - maybe a 1000 lines of free code included for the price of one. But, doesn't work. multi_pass is a forward_trasversal iterator while regex_token_iterator requires a bidirectional_trasversal_iterator. A huge disappoint to come soooo close. Thinking about it, this problem must come very often. How is it usually addressed? There must be a simple bridge across this. In a pinch, I'll just have to load the whole file into some sort collection, but I prefer the ultimate unlimited file size solution. Robert Ramey

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boost.statechart - a data driven state machine
by dev＠kostiadis.com 30 Mar '09

30 Mar '09

Hello all, I'm using the statechart library to create a generic state machine that I can reuse in a number of projects. I'd like this state machine to be completely data driven because it will massively simplify testing and experimenting with different behaviours (i.e. I won't have to re-compile and produce new executables to try out a simple change). Instead of hard-coding all the states, events, transitions, etc., I would like to read all those in from a config file (text, csv, xml, whatever). I'm pretty sure I can't be the first person to want this. Is there an implementation of this out there somewhere? Are there any docs/links/etc. that will point me to the right direction? Thank you in advance, k.

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Problem using Boost->String->Split
by professor rumsdiegeige 30 Mar '09

30 Mar '09

Hello, using Visual Studio 2005 and Boost 1.31, I'm trying to compile this: #include <boost/algorithm/string.hpp> #include <boost/algorithm/string/split.hpp> #include <vector> #include <string> using namespace boost::algorithm; typedef vector< string > split_vector_type; split_vector_type SplitVec; std::string r = std::string(sc); boost::algorithm::split( SplitVec, r, boost::algorithm::is_any_of(sep) ); But I get: error C2039: 'iterator': is not a member of "global namespace'' in iterator.hpp 37 What's wrong here? Thanx! Sabine Lorentz

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Re: [Boost-users] Using boost regex dll in code
by John Maddock 30 Mar '09

30 Mar '09

> If I have the boost_regex 1_38 dll and lib for VC 8, what steps do I need > to > take in order to use it in my code? Is there anything else that I need > other than one of those? The headers would be a good start :-) You will need to define BOOST_REGEX_DYN_LINK when building so that the regex lib knows to import code from a dll, otherwise the default is for it to expect to static link. And also note that there are two dll's for VC8, one for the debug runtime and one for the release runtime. HTH, John.

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[Intrusive] augmenting red black trees
by George Slavov 30 Mar '09

30 Mar '09

I want to know if it's possible to augment the red black tree structure offered by Boost.Intrusive. Specifically I need each node to contain some information like the max value of the subtree rooted at that node and this information should be updated during insert/delete operations. This is a fairly common thing, allowing you to do logarithmic queries that are specific to certain trees, so I'm surprised I couldn't find anything about it in the Boost.Intrusive docs. Regards, George Slavov

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Thread local storage
by Oliver Abert 30 Mar '09

30 Mar '09

Hi Everyone, I am using Boost Threads (1.38) as threading library and I also use the thread_specific_ptr to store a minor amount of data per thread (I think currently it is like 5 different pointer values per thread). Technically everything works out fine, but I am having a performance problem on Mac OS X. On Linux the performance is 10 times faster than on Mac OS. If I use pthreads on Mac OS I have identical performance to the Linux version. Both versions are running on the same machine using 8 threads both. Is there any known problem with shared pointers on Mac OS? I have tried different versions of boost, compiled it myself and also used macports - every time same results on Mac OS. Any hit or possible workaround is very welcome :) Thanks and regards, Oliver

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Re: [Boost-users] Using boost regex dll in code
by dhruva 30 Mar '09

30 Mar '09

Header files corresponding to regex and the dependencies if any (can be found through bcp) -dhruva ________________________________ From: "Green, Jason M NSWCDL, W33" <jason.m.green3(a)navy.mil> To: boost-users(a)lists.boost.org Sent: Monday, 30 March, 2009 6:12:41 PM Subject: [Boost-users] Using boost regex dll in code If I have the boost_regex 1_38 dll and lib for VC 8, what steps do I need to take in order to use it in my code? Is there anything else that I need other than one of those? Jason Unlimited freedom, unlimited storage. Get it now, on http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/

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Using boost regex dll in code
by Green, Jason M NSWCDL, W33 30 Mar '09

30 Mar '09

If I have the boost_regex 1_38 dll and lib for VC 8, what steps do I need to take in order to use it in my code? Is there anything else that I need other than one of those? Jason

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