On Mon, Jan 09, 2006 at 06:11:59PM -0500, Steven N. Hirsch wrote:
> On Mon, 9 Jan 2006, Jeremy White wrote:
>
> > Given this code:
> >
> > {
> > my $variable;
> > sub mysub {
> > # ... accessing $variable
> > }
> > }
> >
> > from:
> >
> > http://www.unix.org.ua/orelly/perl/cookbook/ch10_04.htm
Careful. Some people won't talk very nicely of you if you go bandying
URLs like that around.
> > Is there a way to get hold of the SV for $variable and manipulate it via XS?
> >
> > I want to be able to write the contents of $variable in XS, then call mysub
> > via XS and then read the contents of $variable afterwards ($variable needs
> > to
> > remain a closure as it is shared with other subs in the same block - the
> > block
> > is evaled into existence during runtime).
>
> Since lexical variables don't appear in the symbol table, the only way I
> know of to access it from XS would be to stash a reference somewhere and
> pass that to the XS routine.
You could take a look at the code in PadWalker on CPAN to get some
ideas, I think.
> Also, I may have simply been up too long,
> but I don't believe your example represents a closure. Only (1) instance
> of 'mysub' will exist and it's present in the package's symbol table.
The docs (used to?) talk about closures being anonymous subroutines, but
I think most people nowadays would says that mysub closes over $variable
and hence it is a closure.
--
Paul Johnson - [EMAIL PROTECTED]
http://www.pjcj.net
