[Python-Dev] Some questions about maintenance of the regular expression code.

[M.-A. Lemburg]

Gary Herron wrote:
> On Wednesday 26 February 2003 01:08 am, M.-A. Lemburg wrote:
> 
>>Gary Herron wrote:
>>
>>>The first glance at the regular expression bug list and the _sre.c
>>>code results in the observation that several of the bugs are related
>>>to running over the recursion limit.  The problem comes from using a
>>>pattern containing ".*?" in a situation where it is expected to match
>>>many thousands of characters.  Each character matched by ".*?" causes
>>>one level or recursion, quickly overflowing the recursion limit.
>>
>>Wouldn't it be possible for the RE compiler to issue a warning in
>>case these kind of patterns are used ? This would be much more helpful
>>than trying to work-around the user problem.
> 
> I think not.  It's not the pattern that's the problem.  A pattern
> containing ".*?" is perfectly legitimate and useful. 

Hmm, could you explain where ".*?" is useful ?

> The problem
> arises when the pattern is used on a string which has thousands of
> characters which match.  By that point the RE compiler is right out of
> the picture.

-- 
Marc-Andre Lemburg
eGenix.com

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