Pathological regular expression

Steven D'Aprano steve at REMOVE-THIS-cybersource.com.au
Sat Apr 11 19:40:33 CEST 2009


On Sat, 11 Apr 2009 08:40:03 -0700, John Machin wrote:

>> To my mind, this is a bug in the RE engine. Is there any reason to not
>> treat it as a bug?
> 
> IMHO it's not a bug -- s/hang/takes a long time to compute/
> 
> Just look at it: 2 + operators and 3 * operators ... It's one of those
> "come back after lunch" REs.

Well, it's been running now for about two and a half hours, that's a 
rather long lunch. And despite MRAB's assertion, it *cannot* be 
interrupted by ctrl-C. That means that to all intents and purposes, the 
interpreter has locked up for the duration of the calculation, which may 
be days or weeks for all I know.



-- 
Steven



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