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Postings from May 2010
On Mon, Apr 12, 2010 at 05:00:49PM -0400, Eric Brine wrote:
> On Sun, Apr 11, 2010 at 3:46 PM, Vincent Pit <perl@profvince.com> wrote:
>
> >
> > > There are a couple of long-standing open tickets (from Michael Schwern)
> > > to the effect that with tied arrays and hashes,
> > > local @tied
> > > doesn't DWIM (RT #7938, #7939).
> > >
> > > The current behaviour of local @tied is to create a new array, store it
> > > in the ARRAY slot of *tied, and then I<attach tie magic to the new array
> > > too>. This makes the local essentially a noop, and gives the following
> > > behaviour:
> > >
> >
> > > My preferences in descending order are 2,1,3.
> > >
> >
> > Just a couple of notes to add to the discussion :
> > - localized tied scalars remains tied.
> >
>
> Which is quite annoying.
>
> sub func {
> my ($fn) = @_;
> local $_;
> open(my $fh, '<', $fn) or die;
> while (<$fh>) {
> ...
> }
> }
>
> for ($foo, $bar) {
> func($_);
> }
>
> Do you see the bug in the above? Despite an attempt to privatize $_, the
> while is loop is unknowingly calling magic some modules away because a
> variable that's not even in the current function ($bar) happens to be tied.
>
> my $_; avoids the common case of this problem.
with commits
5afa72af5aa99c40932771ad390abf5ba229611b
191ad7eff570fc96c93993e4358f83e2033365d6
these localisation actions now leave you with an untied thinggy:
local @tied_array
local %tied_hash
local $tied_scalar
--
A walk of a thousand miles begins with a single step...
then continues for another 1,999,999 or so.
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