> Ban Perl hooks into regexes
>
> =head1 ABSTRACT
>
> Remove C<?{ code }>, C<??{ code }> and friends.
>
At first, I thought you were crazy, then I read
>It would be preferable to keep the regular expression engine as
>self-contained as possible, if nothing else to enable it to be used
>either outside Perl or inside standalone translated Perl programs
>without a Perl runtime.
Which makes a lot of sence in the development field.
Tom has mentioned that the reg-ex engine is getting really out of hand;
it's hard enough to document clearly, much less be understandible to the
maintainer (or even the debugger).
A lot of what is trying to happen in (?{..}) and friends is parsing. To
quote Star Trek Undiscovered Country, "Just because we can do a thing,
doesn't mean we should." Tom and I have commented that parsing should be
done in a PARSER, not a lexer (like our beloved reg-ex engine). RecDescent
and Yacc do a wonderful job of providing parsing power within perl.
I'd suggest you modify your RFC to summarize the above; that (?{}) and
friends are parsers, and we already have RecDescent / etc. which are much
easier to understand, and don't require too much additional overhead.
Other than the inherent coolness of having hooks into the reg-ex code, I
don't really see much real use from it other than debugging; eg (?{ print
"Still here\n" }). I could go either way on the topic, but I'm definately
of the opinion that we shouldn't continue down this dark path any further.
-Michael
