Your results are the scalar context of keys(). I'm talking about something like the following statement:
if (%h) {
...do something with a non-empty hash
}
As far as I can tell, there is no method in the tied hash class that is invoked for this. Try the following module to test:
package TieTest;
use strict;
use Carp;
use vars qw(@ISA);
use Tie::Hash;
@ISA = qw( Tie::StdHash );
sub STORE { notify('STORE'); shift->SUPER::STORE(@_); }
sub FETCH { notify('FETCH'); shift->SUPER::FETCH(@_); }
sub FIRSTKEY { notify('FIRSTKEY'); shift->SUPER::FIRSTKEY(@_); }
sub NEXTKEY { notify('NEXTKEY'); shift->SUPER::NEXTKEY(@_); }
sub EXISTS { notify('EXISTS'); shift->SUPER::EXISTS(@_); }
sub DELETE { notify('DELETE'); shift->SUPER::DELETE(@_); }
sub CLEAR { notify('CLEAR'); shift->SUPER::CLEAR(@_); }
sub notify { print shift, " here.\n"; }
1;
You can use it with something like this:
#!/usr/bin/perl
use TieTest;
tie %h, 'TieTest';
grep($h{$_} = $_, 0 .. 9);
print "Scalar test:\n";
$c = %h;
print "count is $c\n";
Any ideas?
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