Add tests, clean up Tie::Scalar

[perl5.git] / lib / Tie / RefHash.pm

diff --git a/lib/Tie/RefHash.pm b/lib/Tie/RefHash.pm
index 20f0d58..8555635 100644 (file)
--- a/lib/Tie/RefHash.pm
+++ b/lib/Tie/RefHash.pm
@@ -1,11 +1,73 @@
-#
-# Tie/RefHash.pm - use references as hash keys 
-#
-# Documentation at the __END__
-#
-
-require 5.004;
 package Tie::RefHash;
+
+our $VERSION = '1.21';
+
+=head1 NAME
+
+Tie::RefHash - use references as hash keys
+
+=head1 SYNOPSIS
+
+    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;
+    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";
+    }
+
+=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;
@@ -22,7 +84,17 @@ sub TIEHASH {
 
 sub FETCH {
   my($s, $k) = @_;
-  (ref $k) ? $s->[0]{"$k"}[1] : $s->[1]{$k};
+  if (ref $k) {
+      if (defined $s->[0]{"$k"}) {
+        $s->[0]{"$k"}[1];
+      }
+      else {
+        undef;
+      }
+  }
+  else {
+      $s->[1]{$k};
+  }
 }
 
 sub STORE {
@@ -48,7 +120,8 @@ sub EXISTS {
 
 sub FIRSTKEY {
   my $s = shift;
-  my $a = scalar(keys %{$s->[0]}) + scalar(keys %{$s->[1]});
+  keys %{$s->[0]};     # reset iterator
+  keys %{$s->[1]};     # reset iterator
   $s->[2] = 0;
   $s->NEXTKEY;
 }
@@ -74,63 +147,16 @@ sub CLEAR {
   %{$s->[1]} = ();
 }
 
-1;
-
-__END__
-
-=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@umich.edu
-
-
-=head1 VERSION
-
-Version 1.2    15 Dec 1996
-
-
-=head1 SEE ALSO
-
-perl(1), perlfunc(1), perltie(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);
+}
 
-=cut
+1;