Sorry, I was too brief. What I meant was in the absence of assigning value to the key
_val: (note the change with comments)
use strict;
use warnings;
use Data::Dumper qw( Dumper );
sub samtregar {
my $p = shift;
my $val = pop;
for my $item (@_) {
$p->{$item} ||= {};
$p = $p->{$item};
}
### $p->{_val} = $val;
}
sub repellent {
my $p = \shift;
my $val = pop;
$p = \$$p->{$_} for @_;
### $$p->{_val} = $val;
}
{
samtregar(my $samtregar={}, qw( a b c d ), 'foo');
repellent(my $repellent, qw( a b c d ), 'foo');
{
local $Data::Dumper::Useqq = 1;
local $Data::Dumper::Terse = 1;
local $Data::Dumper::Indent = 0;
print("samtregar: ", Dumper($samtregar), "\n");
print("repellent: ", Dumper($repellent), "\n");
}
}
__END__
samtregar: {"a" => {"b" => {"c" => {"d" => {}}}}}
repellent: {"a" => {"b" => {"c" => {"d" => undef}}}}
while the nested hashes are being built, it doesn't leave an empty
{} around. This behavior could be desirable.
I didn't mean to say that mine doesn't vivify. It's almost the same, just subtly different as shown above.
Hmmm ... as for the fetchers, shouldn't it be more consistent with:
use strict;
use warnings;
use Data::Dumper qw( Dumper );
sub samtregar_fetcher {
my $p = shift;
for my $item (@_) {
### last if !$p->{$item};
$p->{$item} ||= {};
$p = $p->{$item};
}
return $p->{_val}
}
sub repellent_fetcher {
my $p = \shift;
### my $val = pop;
$p = \$$p->{$_} for @_;
return $$p->{_val};
}
{
samtregar_fetcher(my $samtregar={}, qw( a b c d ));
repellent_fetcher(my $repellent, qw( a b c d ));
{
local $Data::Dumper::Useqq = 1;
local $Data::Dumper::Terse = 1;
local $Data::Dumper::Indent = 0;
print("samtregar: ", Dumper($samtregar), "\n");
print("repellent: ", Dumper($repellent), "\n");
}
}
__END__
samtregar: {"a" => {"b" => {"c" => {"d" => {}}}}}
repellent: {"a" => {"b" => {"c" => {"d" => {}}}}}
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