NAME¶
Tie::RefHash - use references as hash keys
SYNOPSIS¶
require 5.004;
use Tie::RefHash;
tie HASHVARIABLE, 'Tie::RefHash', LIST;
tie HASHVARIABLE, 'Tie::RefHash::Nestable', LIST;
untie HASHVARIABLE;
DESCRIPTION¶
This module provides the ability to use references as hash keys if you first
"tie" the hash variable to this module. Normally, only the keys of
the tied hash itself are preserved as references; to use references as keys in
hashes-of-hashes, use Tie::RefHash::Nestable, included as part of
Tie::RefHash.
It is implemented using the standard perl TIEHASH interface. Please see the
"tie" entry in
perlfunc(1) and
perltie(1) for more
information.
The Nestable version works by looking for hash references being stored and
converting them to tied hashes so that they too can have references as keys.
This will happen without warning whenever you store a reference to one of your
own hashes in the tied hash.
EXAMPLE¶
use Tie::RefHash;
tie %h, 'Tie::RefHash';
$a = [];
$b = {};
$c = \*main;
$d = \"gunk";
$e = sub { 'foo' };
%h = ($a => 1, $b => 2, $c => 3, $d => 4, $e => 5);
$a->[0] = 'foo';
$b->{foo} = 'bar';
for (keys %h) {
print ref($_), "\n";
}
tie %h, 'Tie::RefHash::Nestable';
$h{$a}->{$b} = 1;
for (keys %h, keys %{$h{$a}}) {
print ref($_), "\n";
}
THREAD SUPPORT¶
Tie::RefHash fully supports threading using the "CLONE" method.
STORABLE SUPPORT¶
Storable hooks are provided for semantically correct serialization and cloning
of tied refhashes.
RELIC SUPPORT¶
This version of Tie::RefHash seems to no longer work with 5.004. This has not
been throughly investigated. Patches welcome ;-)
LICENSE¶
This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself
MAINTAINER¶
Yuval Kogman <nothingmuch@woobling.org>
AUTHOR¶
Gurusamy Sarathy gsar@activestate.com
'Nestable' by Ed Avis ed@membled.com
SEE ALSO¶
perl(1),
perlfunc(1),
perltie(1)