Re^3: Autovivification sucking the life out of me

Tell you what: It's perplexing to me the other way around!

Until 2 days ago I thought something like
if ($foo{'BAR'}) ...
would already vivify that hash entry.

But then I learned in the Chatter Box that it doesn't in perl 5.8 (or maybe a bit earlier).

And now I did a test. Compare the output

use Data::Dumper;
%foo=(BAZ=>1);
print Dumper \%foo if $foo{BAR} || 1;
print Dumper \%foo if @foo{BAR,BAZ} || 1;
[download]

Output:
$VAR1 = { 'BAZ' => 1 }; $VAR1 = { 'BAZ' => 1 };

use Data::Dumper;
%foo=(BAZ=>1);
print Dumper \%foo if call($foo{BAR});
print Dumper \%foo if call(@foo{BAR,BAZ});
sub call { return 1 }
[download]

Output:
$VAR1 = { 'BAZ' => 1 }; $VAR1 = { 'BAR' => undef, 'BAZ' => 1 };

So it's really the fact that the slice is used in a subroutine call. When you replace call with print, autovivification does not happen

So now I ask myself: Is there a bug and you are certified bugfinder!? ;-)

s$$([},&%#}/&/]+}%&{})*;#$&&s&&$^X.($'^"%]=\&(|?*{%
+.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e