Re: Pathological regexp match
От | Michael Glaesemann |
---|---|
Тема | Re: Pathological regexp match |
Дата | |
Msg-id | 9B3645EE-2DC2-4379-AC00-B71F8C5D3E55@myyearbook.com обсуждение исходный текст |
Ответ на | Re: Pathological regexp match (Alvaro Herrera <alvherre@commandprompt.com>) |
Список | pgsql-hackers |
On Jan 28, 2010, at 23:21 , Alvaro Herrera wrote: > I think the reason for this is that the first * is greedy and thus the > entire expression is considered greedy. The fact that you've made the > second * non-greedy does not ungreedify the RE ... Note the docs say: > > The above rules associate greediness attributes not only with > individual quantified atoms, but with branches and entire REs > that contain quantified atoms. What that means is that the > matching is done in such a way that the branch, or whole RE, > matches the longest or shortest possible substring as a whole. Interesting. Thanks for pointing out this section of the docs. I wasn't aware of this twist. > It's late here so I'm not sure if this is what you're looking for: I'm not actually looking for a regexp that works: I was able to accomplish the task I had at hand with a different regexp. I'm just reporting the particular unexpected nastiness we ran into. :) Michael Glaesemann michael.glaesemann@myyearbook.com
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