That's be awesome James. I'd love to see re2j out in the open On Mon, Feb 2, 2015 at 2:20 PM, James Ring <s...@jdns.org> wrote:
> I spoke to one of the authors of re2j, a Google-internal port of the C++ > re2 library. The intention was to open source it but they just haven't got > around to it. > > I may try and get Google to put re2j up on GitHub so you all can take a > look. AFAIK it is heavily used in Google and it has an API that is largely > compatible with java.util.regex. I know from personal experience that one > can often benefit from re2j merely by replacing java.util.regex imports > with the corresponding re2j imports. > > Regards, > James > On Feb 1, 2015 11:44 PM, "Thomas Neidhart" <thomas.neidh...@gmail.com> > wrote: > > > On 02/02/2015 03:25 AM, sebb wrote: > > > I would not wish to move away from Java RE *unless* the RE syntax was > > > the same *and* the implementation was better performing *and* the > > > existing code suffered from poor performance. > > > > > > It might be OK if the alternate implementation was missing some > > > esoteric features, but I would be very wary of using any features that > > > were not in the Java implementation. > > > > > > The likelihood is that the Java implementation will (eventually) > > > become more performant, at which point it would be useful to be able > > > to revert to the Java version. > > > That requires a high degree of compatibilty to reduce the work > involved. > > > > > > It might be more useful to produce a tool that detects inefficient RE > > > usage and suggests improvements. > > > > I just know re2 a bit, but it is a trade-off: > > > > * linear-time evaluation vs. some features (e.g. backreferences) > > > > A comparison between different regular expression implementations can be > > found here: > > > > http://en.wikipedia.org/wiki/Comparison_of_regular_expression_engines > > > > I am pretty sure the regexp implementation in java will not change, > > simply because of backwards compatibility reasons, but such a library > > would be useful as in many cases you do not need these additional > > features but want to ensure that your regular expression will be > > evaluated in linear time. > > > > Thomas > > > > > > > > > > > On 1 February 2015 at 22:35, James Carman <ja...@carmanconsulting.com> > > wrote: > > >> To be clear, I am not advocating this approach. I was merely trying > to > > >> illustrate what a nightmare such an endeavor would be. :) > > >> > > >> On Sunday, February 1, 2015, James Carman <ja...@carmanconsulting.com > > > > >> wrote: > > >> > > >>> You would basically have to pick a canonical regex language if you > > want a > > >>> facade and be able to swap the regex library out. Most of them are > > very > > >>> similar but they are not the same. > > >>> > > >>> On Sunday, February 1, 2015, Gary Gregory <garydgreg...@gmail.com > > >>> <javascript:_e(%7B%7D,'cvml','garydgreg...@gmail.com');>> wrote: > > >>> > > >>>> I think we'll need some clear performance advantages documented as > > well as > > >>>> any compatibility issues. > > >>>> > > >>>> This begs for a facade API IMO. I would not want to recode my app > > just to > > >>>> test one vs. the other, it should be pluggable. > > >>>> > > >>>> Gary > > >>>> > > >>>> On Sat, Jan 31, 2015 at 10:58 AM, Benson Margulies < > > bimargul...@gmail.com > > >>>>> > > >>>> wrote: > > >>>> > > >>>>> 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 > > >>>>> > > >>>>> > > >>>> > > >>>> > > >>>> -- > > >>>> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org > > >>>> Java Persistence with Hibernate, Second Edition > > >>>> <http://www.manning.com/bauer3/> > > >>>> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> > > >>>> Spring Batch in Action <http://www.manning.com/templier/> > > >>>> Blog: http://garygregory.wordpress.com > > >>>> Home: http://garygregory.com/ > > >>>> Tweet! http://twitter.com/GaryGregory > > >>>> > > >>> > > > > > > --------------------------------------------------------------------- > > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: dev-unsubscr...@commons.apache.org > > For additional commands, e-mail: dev-h...@commons.apache.org > > > > > -- about.me/benmccann
