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Re^3: Autovivification sucking the life out of me

by Skeeve (Parson)
on Oct 14, 2005 at 08:17 UTC ( #500162=note: print w/replies, xml ) Need Help??


in reply to Re^2: Autovivification sucking the life out of me
in thread 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;
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 }
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

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