On Sun, 01 Oct 2000 18:43:27 +0100, Hugo wrote:
>:This makes the implementation very tricky. I
>:wouldn't be surprised if precisely this feature is the main reason why
>:the current implementation is so notoriously unstable.
>
>I'm not aware of any instability caused by this. The instability is
>caused by various other factors, discussed at length on p5p.
I'll remove that in the final RFC. I'll just say that implementation of
"local" is nontrivial.
>:=head2 /(?(condition)yes-pattern|no-pattern)/
>
>The simplest form of this is (?(1)yes|no). This is rather harder to
>emulate with other mechanisms without running to eval. OTTOMH it is
>equivalent to (??{ defined($1) ? 'yes' : 'no' }).
You're forgetting about assertions. Now *that* is something starge to
overlook. ;-)
(?:(?{defined $1})yes|(?{not defined $1})no)
--
Bart.
