Hi Benson! I wouldn't be able to help at the moment, but some years ago I had a performance issue in a Nutch crawler with regexes [1] and found about this other library that you mentioned I think. Are you talking about ORO? I ended up changing the regex and never had a chance to play with ORO or other libraries to see if there was any advantage over not using JRE's regex API. Recently I had another performance problem with Apache Hive SerDe and performance problems and fixed it by changing the storage format and simplifying the regex. Have you done any performance comparison with your code and other libraries? More or less like this [2]? Maybe this library could be used as an alternative in Nutch, Commons Crawl or in other projects when performance was important. Lastly, I'm using OpenRegex (GPLv3) [3] in a project, in combination with Apache OpenNLP. It is a "regular expression language and engine" that users can use to match string and NLP tags. For example: <string='My Company'> <lemma='be'> <postag='RB'>* (<adjective>: <postag='JJ'>)) Where <lemma='be'> will match any form of be/is/was/were/etc, <postag='RB'>* one or more adverbs and the last part of the expression will find a named token "adjective" (JJ is the Penn Tree Bank part of speech tag for adjectives). Not sure if your library will work only with text or will support any other approaches too. OpenRegex has some TODO's in the GitHub Wiki but hasn't been updated in a while. Maybe if your library could work similarly to OpenRegex, it could be incorporated in Apache OpenNLP too. Even the LanguageTool team demonstrated some interest in experimenting it [4]. Just food for thought :-)Bruno [1] https://issues.apache.org/jira/browse/NUTCH-1014[2] http://tusker.org/regex/regex_benchmark.html[3] https://github.com/knowitall/openregex[4] http://sourceforge.net/p/languagetool/mailman/languagetool-devel/thread/69f229c0a58d3245d511dafaa82feafc%40danielnaber.de/#msg31280519 From: Benson Margulies <bimargul...@gmail.com> To: Commons Developers List <dev@commons.apache.org> Sent: Saturday, January 31, 2015 1:58 PM Subject: Anyone interested in regular expressions, again? So, once upon a time, there was a regex library here. It was retired, presumably on the grounds that it was rendered obsolete by the JRE's native support.
However, the JRE's regular expressions have a pretty severe problem; they have unbounded (or at least, very, very, bad) execution time for some combinations of data and regex. To cope with this, we ported the Henry Spencer regular expression library (as found in TCL) from C to Java. Thus: https://github.com/basis-technology-corp/tcl-regex-java Is anyone interested in this? Give or take the possible IP muddle of the original C Code, I could grant it easily. --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org For additional commands, e-mail: dev-h...@commons.apache.org
