freebsd-dev/contrib/perl5/lib/Tie/RefHash.pm
2000-06-25 11:04:01 +00:00

125 lines
1.9 KiB
Perl

package Tie::RefHash;
=head1 NAME
Tie::RefHash - use references as hash keys
=head1 SYNOPSIS
require 5.004;
use Tie::RefHash;
tie HASHVARIABLE, 'Tie::RefHash', LIST;
untie HASHVARIABLE;
=head1 DESCRIPTION
This module provides the ability to use references as hash keys if
you first C<tie> the hash variable to this module.
It is implemented using the standard perl TIEHASH interface. Please
see the C<tie> entry in perlfunc(1) and perltie(1) for more information.
=head1 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";
}
=head1 AUTHOR
Gurusamy Sarathy gsar@activestate.com
=head1 VERSION
Version 1.21 22 Jun 1999
=head1 SEE ALSO
perl(1), perlfunc(1), perltie(1)
=cut
require 5.003_11;
use Tie::Hash;
@ISA = qw(Tie::Hash);
use strict;
sub TIEHASH {
my $c = shift;
my $s = [];
bless $s, $c;
while (@_) {
$s->STORE(shift, shift);
}
return $s;
}
sub FETCH {
my($s, $k) = @_;
(ref $k) ? $s->[0]{"$k"}[1] : $s->[1]{$k};
}
sub STORE {
my($s, $k, $v) = @_;
if (ref $k) {
$s->[0]{"$k"} = [$k, $v];
}
else {
$s->[1]{$k} = $v;
}
$v;
}
sub DELETE {
my($s, $k) = @_;
(ref $k) ? delete($s->[0]{"$k"}) : delete($s->[1]{$k});
}
sub EXISTS {
my($s, $k) = @_;
(ref $k) ? exists($s->[0]{"$k"}) : exists($s->[1]{$k});
}
sub FIRSTKEY {
my $s = shift;
keys %{$s->[0]}; # reset iterator
keys %{$s->[1]}; # reset iterator
$s->[2] = 0;
$s->NEXTKEY;
}
sub NEXTKEY {
my $s = shift;
my ($k, $v);
if (!$s->[2]) {
if (($k, $v) = each %{$s->[0]}) {
return $s->[0]{"$k"}[0];
}
else {
$s->[2] = 1;
}
}
return each %{$s->[1]};
}
sub CLEAR {
my $s = shift;
$s->[2] = 0;
%{$s->[0]} = ();
%{$s->[1]} = ();
}
1;