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Re: Re: Recursive Regex: Update

by robin (Chaplain)
on Apr 24, 2002 at 08:54 UTC ( [id://161544] : note . print w/replies, xml ) Need Help??

in reply to Re: Recursive Regex: Update
in thread Recursive Regex: Update

Oh, I'm not planning to touch the regex engine. That would be lunacy, as you say! Just bypassing the current engine altogether will be much less difficult.

I'm appropriately respectful of your bravery in venturing into the tokeniser. It scares the hell out of me.

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Re^3: Recursive Regex: Update
by demerphq (Chancellor) on Sep 13, 2006 at 10:11 UTC

    My things have come a long way since this thread. :-)

    Id say hacking this into the regex engine is probably a good thing. And i suspect that its probably easier to do so than to hack PCRE into perl. Even perls own regex engine is not easily properly pluggable due to a lack of hooks into sv.c's re_dup(). I suspect that getting the PCRE engine would have the same problems. Which actually reminds me, we need to make sure that Perl 5.10 has the appropriate hooks so that making pluggable regex engines for perl 5.10 and later is easier.


      You're right that things have come a long way. I'm not scared of the tokeniser any more, for example. The regex code still gives me the willies, but I guess you're happier with it than you were in 2002. :-) The most unsatisfactory thing about the PCRE recursion code is that the match data is still a plain list, when morally it ought to be a tree. If we could get that sorted, you could write an entire parser as a single regex!

        The recursive regex patch was applied to blead as 28939. If you feel up to it it would be cool if you could review the documentation on it and make whatever changes you think are needed based on your experience with the PCRE stuff.