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Re: [PATCH op.c op.h pp_sys.c t/op/local.t pod/perlfunc.pod] local chdir()

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From:
Bryan C . Warnock
Date:
September 1, 2001 11:29
Subject:
Re: [PATCH op.c op.h pp_sys.c t/op/local.t pod/perlfunc.pod] local chdir()
Message ID:
01090114263609.01071@wakko.idiocity.nut
On Saturday 01 September 2001 02:15 pm, you wrote:
> > I'm still not clear why you specifically want to introduce new grammar
> > to implement this, as opposed to, say, the tied example provided
> > earlier.
>
> Because, you have the weird caveat of having to keep the returned
> variable around.
>
>     use File::chdir;
>
>     {
>         my $old_dir = chdir($dir);
>     }
>
> The wires are showing through the magician's trick.

Wouldn't that be:

use File::chdir;

{
    local $cwd = $dir;     # Assuming $cwd FETCH and STORE manipulated chdir
}

?

>
> > What are the advantages of having 'local' work with chdir(), compared to
> > the disadvantages of having variable scope declarators that are no
> > longer limited to variables, but now work with functions?
>
> That would be probably the best way to do it.  Have some sort of hook
> that lets you add scope destructors to things.  I have no idea how to
> do it.  Sounds complicated, <obvious troll>probably will never get
> done.</obvious troll>

Yeah, I couldn't figure it out, either, when I was trying to change the 
default shell.

{snip}
> A)  I have no idea how to do that.

Fair 'nuff.

> B)  More importantly, *that's* the sort of major redesign I'll leave for
>     Perl 6.
>
> I don't want to redesign the language.  I just want to get some work
> done.

It seems to me munging local to handle some functions is more of a language 
change than adding another variable, since the generic behavior of variables 
is well-known.

Also, one comment on your patch - I saw a doc change for chdir, but I didn't 
see one for local.

-- 
Bryan C. Warnock
bwarnock@capita.com

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