[erlang-questions] re: re:pain (and stripping whitespace from text)

Hynek Vychodil <>
Thu Mar 18 17:37:35 CET 2010


On Sun, Mar 14, 2010 at 7:35 AM, Robert Virding <> wrote:
> On 14 March 2010 03:45, Jayson Vantuyl <> wrote:
>> Also, note that backtracking and recursion can create very undesirable behavior in terms of stack usage and execution time.  This is so problematic that Google has written a special regex library that uses research in automata theory to make it behave better.  See here:
>>
>> RE2:  http://code.google.com/p/re2/
>
> I did a regexp version in Erlang based on these principles and it is
> actually time linear in the size of the input. It is fun to see it zip
> through what would be for Perl/PCRE a super backtracking pathological
> case in a flash. One day when I get the time to cleanup the code I
> will release it.

I thought about similar in context of
http://shootout.alioth.debian.org/u32q/performance.php?test=regexdna
but with limited functionality and as specialized parse
transformation. But I didn't because I was too busy.

>
> Robert
>
> ________________________________________________________________
> erlang-questions (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:
>
>



-- 
--Hynek (Pichi) Vychodil

Analyze your data in minutes. Share your insights instantly. Thrill
your boss.  Be a data hero!
Try GoodData now for free: www.gooddata.com


More information about the erlang-questions mailing list