From: Roman Hausner <roman.hausner@...>
Date: 2006-07-28T07:14:12+09:00
Subject: Re: Slow regular expressions :(

Caleb Clausen wrote:
> If you take out the first \s* (or move it outside the parens), the
> slowness goes away. That first \s* isn't needed. Another trick that
> may help here is changing the *'s to +'s.
> 
> This is a case of pathological backtracking. Usually, these things are
> solved by carefully tuning the Regexp, rather than expecting the
> Regexp engine to fix it...
> 
No. I am not looking for help on regular expressions here and I know
that this particular expression could be optimized. I also know that
some regular expressions with backtracking can get exponentially slow.

However, regular expression can get generated automatically or there
could be other reasons why an optimization a la perl is helpful.

The example simply points out that ruby uses a strategy that does not do
the optimization that is present in perl. My question was, whether Ruby
is going to fix this.

If you can answer that question, I would apreciate it. If not, maybe 
somebody
else can.

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