Re^5: Help with Double Double Quotes regular expression (failing)


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Re^5: Help with Double Double Quotes regular expression (failing)

by pKai (Priest)

on Apr 02, 2007 at 22:23 UTC ( [id://607935]=note: print w/replies, xml )

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in reply to Re^4: Help with Double Double Quotes regular expression (imprecise)
in thread Help with Double Double Quotes regular expression

I noticed that your sample $s is a non-matching one.

Did you take that on purpose to emphasise on cutting off backtracking in the failing case?

When I balance the (double)quotes in $s by adding one in last position (directly before the closing parentheses of q,) "straight" seems to have a slight edge over "cut"

             Rate      cut straight
cut      110876/s       --     -13%
straight 127147/s      15%       --
[download]

I got similar figures as you for your original $s

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Re^6: Help with Double Double Quotes regular expression (failing) by bart (Canon) on Apr 02, 2007 at 22:28 UTC
I noticed that your sample $s is a non-matching one. Did you take that on purpose to emphasise on cutting off backtracking in the failing case? I did. Because it's a well known fact (see the owl book AKA Jeffrey Friedl's "Mastering Regular Expressions", for example) that the pathetic case typically rears its ugly head when matches fail. That was the case in my Javascript code, too.	[reply]

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