At 3:05 PM +0100 2/13/02, Angel Faus wrote:
>Dan wrote:
>>Yep, I've seen their plans. It's less an issue for us, at least as
>>far as globals are concerned, since we'll be doing that with
>>lexicals. (Python not having lexicals, after all) Globals are a bit
>>more interesting, since bytecode-loaded modules can't guarantee
>>global positions, since there's no way of knowing at runtime what's
>>been stuffed into the global tables already.
>>
>>Anyway, doing this with lexicals, which we can know at compile time,
> >will get us these speed boosts, and has been on the list for ages.
>
>Oh, I see. Just two quick questions:
>
>* will sub definition create globals? I mean, does "sub a {}" create
>a function PMC and store it into the "a" lexical? or will there be
>a separate mechanism for functions?
sub a{} is global. my sub a{} is lexical. A function PMC's created in
either case, the only question is where it's stuck.
>* Is there any chance that lexicals get mapped to registers, at least
>in the cases where the block doesn't use any dynamic features (MY%,
>eval, etc..)?
Absolutely. Optimizing away lexicals entirely is an issue for the
optimizer, and there are some potential problems with doing it in
perl (since you can snoop almost anywhere, there are a limited number
of places you can optimize variables away entirely). But other
languages with less introspection can definitely do that without a
problem.
--
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
