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Re: my $@ - a proposal

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On Jun 27, 2008, at 2:39 PM, Jan Dubois wrote:
> On Fri, 27 Jun 2008, David Nicol wrote:
>> On Fri, Jun 27, 2008 at 2:10 PM, Graham Barr <gbarr@pobox.com> wrote:
>>
>>> localizing it is not right, because you only want to restore it if  
>>> it is
>>> cleared. If you localize and DESTROY dies, the $@ will get  
>>> restored and you
>>> will never see.
>>
>> the draft patch doesn't really localize in the C<local> sense because
>> it doesn't clear ERRSV, but merely takes a copy of it and the  
>> restores
>> the value to ERRSV when ERRSV winds up false after the destructor
>> runs.
>
> That's not really good enough though.  You need to restore ERRSV  
> whenever
> the initial substring of the saved ERRSV doesn't match the current  
> ERRSV
> (making sure that only cleanup errors have been appended).
You cannot do that. Where does it say that $@ is a string?
If DESTROY returns and $@ is set, then it should be left. If $@ has  
been cleared then it needs to be restored to what it was before  
DESTROY was called.
> Otherwise you still end up with the wrong value in $@ when DESTROY
> (or any code called from it) uses an eval that catches a die():
>
>    sub foo::DESTROY { eval {require bar} }
>    eval { my $foo = bless [] => "foo"; die "I'm dead" };
>    print "\$\@ is $@\n";
>
> With your patch you at least end up with a TRUE value in $@, but the
> actual content is still not what you would expect.
What do you expect ?
Graham.

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• my $@ - a proposal by Yuval Kogman
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Mark Mielke
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by Graham Barr
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by Ben Morrow
• Re: my $@ - a proposal by Graham Barr
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Johan Vromans
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Rafael Garcia-Suarez
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Ben Morrow
• Re: my $@ - a proposal by Elliot Shank
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Juerd Waalboer
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Graham Barr
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by Aristotle Pagaltzis
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Raphael_Manfredi
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Raphael_Manfredi
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Raphael_Manfredi
• Re: my $@ - a proposal by Dr.Ruud
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Sean O'Rourke
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Steffen Mueller
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by David Golden
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Aristotle Pagaltzis
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Yuval Kogman
• Re: my $@ - a proposal by Dr.Ruud
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by David Cantrell
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Moritz Lenz
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Moritz Lenz
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Moritz Lenz
• Re: my $@ - a proposal by Sam Vilain
• Re: my $@ - a proposal by Abigail
• Re: my $@ - a proposal by Mark Mielke
• Re: my $@ - a proposal by Aristotle Pagaltzis
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Nicholas Clark
• Re: my $@ - a proposal by David Nicol
• RE: my $@ - a proposal by Jan Dubois
• Re: my $@ - a proposal by David Nicol
• Re: my $@ - a proposal by Reini Urban
• Re: my $@ - a proposal by Dr.Ruud
• Re: my $@ - a proposal by Sam Vilain