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 the hash variable to this module. It is implemented using the standard perl TIEHASH interface. Please see the C 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;