What is a hash slice and how is one written in Perl?
A means of selecting multiple elements for fetching or setting. An example would be @hash{ 'key1', 'key2', ... }. See perldata for details.
if a delete function in a Perl program specifies a slice, will the interpreter break it up into individual calls to DELETE?
Yes.
{
package Tester;
use Tie::Hash qw();
our @ISA = 'Tie::StdHash';
sub DELETE {
my $self = shift;
print("DELETE @_\n");
$self->SUPER::DELETE(@_)
}
}
{
tie my %hash, 'Tester';
%hash = (
a => 1,
b => 2,
c => 3,
d => 4,
);
delete @hash{qw( b c )};
print(join(' ', keys %hash), "\n");
}
DELETE b
DELETE c
a d
If there are other pages that cover this subject, please tell me.
Update: Formatting changes. Switched from using array to using hash in DELETE test.
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