From: Tammo Tjarks <tammo@...>
Date: 2007-09-08T18:40:07+09:00
Subject: Re: compatibility in regexps between perl and ruby

Hi,

thanks for the quick answer, does "oniguruma" support all regexps of perl?
I stumbled over another one, where ?(..) is used, where .. is some check ( a
number). It referes to the revious matches and matches the following
expression only if the expression in the by .. given has matched.
E.g. 
/(foo) (\() (\+)  ?(2) (\))/ 
matches the closing ) only if a opening occured (referes to the matching in
the second (..)

Best regards,
Tammo

come wrote:

> Hi,
> 
> You are right: the zerowidth lookbehind isn't still implemented in
> Ruby 1.8. We have to wait for the new engine "oniguruma", and the 1.9
> version.
> 
> You can install oniguruma as a gem in Ruby 1.8.
> 
> Come
> 
> On 8 sep, 11:10, Tammo Tjarks <ta...@tammo-tjarks.de> wrote:
>> Hello,
>> I try to translate some perl to ruby and assumed so far that the regexps
>> are compatible. But it seems that there are some only available in perl.
>> Is there something comparable to
>> (?<!...)
>> also in ruby (is a zerowidth lookbehind, so
>> /(?<!test)moin/ would only match moin if no test preceeds.
>>
>> Regards,
>> Tammo