*** /usr/lib/perl5/5.00503/Tie/RefHash.pm	Thu Aug 10 20:36:04 2000
--- RefHash.pm	Thu Nov  2 14:29:56 2000
***************
*** 9,25 ****
      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;
--- 9,34 ----
      require 5.004;
      use Tie::RefHash;
      tie HASHVARIABLE, 'Tie::RefHash', LIST;
+     tie HASHVARIABLE, 'Tie::RefHash::Nestable', 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.  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::Hash.
  
  It is implemented using the standard perl TIEHASH interface.  Please
  see the C<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.
+ 
  =head1 EXAMPLE
  
      use Tie::RefHash;
***************
*** 36,41 ****
--- 45,55 ----
         print ref($_), "\n";
      }
  
+     tie %h, 'Tie::RefHash::Nestable';
+     $h{$a}->{$b} = 1;
+     for (keys %h, keys %{$h{$a}}) {
+        print ref($_), "\n";
+     }
  
  =head1 AUTHOR
  
***************
*** 68,74 ****
  
  sub FETCH {
    my($s, $k) = @_;
!   (ref $k) ? $s->[0]{"$k"}[1] : $s->[1]{$k};
  }
  
  sub STORE {
--- 82,98 ----
  
  sub FETCH {
    my($s, $k) = @_;
!   if (ref $k) {
!       if (defined $s->[0]{"$k"}) {
! 	  $s->[0]{"$k"}[1];
!       }
!       else {
! 	  undef;
!       }
!   }
!   else {
!       $s->[1]{$k};
!   }
  }
  
  sub STORE {
***************
*** 118,123 ****
--- 142,159 ----
    $s->[2] = 0;
    %{$s->[0]} = ();
    %{$s->[1]} = ();
+ }
+ 
+ package Tie::RefHash::Nestable;
+ use vars '@ISA'; @ISA = qw(Tie::RefHash);
+ 
+ sub STORE {
+   my($s, $k, $v) = @_;
+   if (ref($v) eq 'HASH' and not tied %$v) {
+       my @elems = %$v;
+       tie %$v, ref($s), @elems;
+   }
+   $s->SUPER::STORE($k, $v);
  }
  
  1;