Re: RFC 308 (v1) Ban Perl hooks into regexes

Perl6 RFC Librarian <[email protected]> writes:

> This and other RFCs are available on the web at
>   http://dev.perl.org/rfc/
> 
> =head1 TITLE
> 
> Ban Perl hooks into regexes
> 
> =head1 VERSION
> 
>   Maintainer: Simon Cozens <[email protected]>
>   Date: 25 Sep 2000 
>   Mailing List: [email protected]
>   Number: 308
>   Version: 1
>   Status: Developing
> 
> =head1 ABSTRACT
> 
> Remove C<?{ code }>, C<??{ code }> and friends.
> 
> =head1 DESCRIPTION
> 
> The regular expression engine may well be rewritten from scratch or
> borrowed from somewhere else. One of the scarier things we've seen
> recently is that Perl's engine casts back its Krakken tentacles into Perl
> and executes Perl code. This is spooky, tangled, and incestuous.
> (Although admittedly fun.)

It's *loads* of fun. Though admittedly, I've not used it in any *real*
code yet...

> 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.
> 
> To do this, we'll have to remove the bits of the engine that call 
> Perl code. In short: C<?{ code }> and C<??{ code }> must die.

You don't *have* to remove 'em. You can just throw an exception during
compilation if some hypothetical 'no regex subs' pragma is there.

-- 
Piers
'063039183598121887134041122600:1917131105:Jaercunrlkso tPh.'=~/^(.{6})*
(.{6})[^:]*:(..)*(..).*:(??{'.{'.$2%$4.'}'})(.)(??{print$5})/x;print"\n"