Author: ph10 Date: To: Zoltán Herczeg CC: pcre-dev@exim.org Subject: Re: [pcre-dev] Remove some restrictions of lookbehind assertions
On Wed, 31 Jul 2019, Zoltán Herczeg wrote:
> You have already convinced me to drop MOVE :) > The question is whether we keep the other construct. Or "rematching" a capturing block in an assertion like fashion would solve this problem better.
I don't think that would solve the original problem for which *napla
was invented. And also, I'm not sure that matching a captured block
would be easy in the interpreter.
I have come round in a full circle on this one. I quite liked the idea
of *MOVE until I spotted the fatal flaw :-) and I was wondering about
whether treating *napla blocks as assertions was correct. However, I
realized that not treating them as assertions would also lead to looping
issues. PCRE2 does allow assertions to be quantified (because Perl
does), but it only ever obeys an assertion 0 or 1 times.
So my current feeling is to leave *napla and *naplb as they are - but I
realize this might be difficult for JIT. They are currently documented
as not supported by JIT, so if you don't want to support these non-Perl
things, I won't complain. :-)
