X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FTie%2FHash.pm;h=86d253d6d647aca27a5c3974777a0b0b189faf40;hb=46471bde41ad0777edf7b89818df6730e8b55c20;hp=397272becec0646a855f879d4e441ac60a10dea6;hpb=1db7d662ab3016c638481dc6ccd6dfc26c968f33;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/Tie/Hash.pm b/lib/Tie/Hash.pm
index 397272b..86d253d 100644
--- a/lib/Tie/Hash.pm
+++ b/lib/Tie/Hash.pm
@@ -1,6 +1,6 @@
 package Tie::Hash;
 
-our $VERSION = '1.00';
+our $VERSION = '1.02';
 
 =head1 NAME
 
@@ -11,7 +11,7 @@ Tie::Hash, Tie::StdHash, Tie::ExtraHash - base class definitions for tied hashes
     package NewHash;
     require Tie::Hash;
 
-    @ISA = (Tie::Hash);
+    @ISA = qw(Tie::Hash);
 
     sub DELETE { ... }		# Provides needed method
     sub CLEAR { ... }		# Overrides inherited method
@@ -20,25 +20,26 @@ Tie::Hash, Tie::StdHash, Tie::ExtraHash - base class definitions for tied hashes
     package NewStdHash;
     require Tie::Hash;
 
-    @ISA = (Tie::StdHash);
+    @ISA = qw(Tie::StdHash);
 
     # All methods provided by default, define only those needing overrides
     # Accessors access the storage in %{$_[0]};
-    # TIEHANDLE should return a reference to the actual storage
+    # TIEHASH should return a reference to the actual storage
     sub DELETE { ... }
 
     package NewExtraHash;
     require Tie::Hash;
 
-    @ISA = (Tie::ExtraHash);
+    @ISA = qw(Tie::ExtraHash);
 
     # All methods provided by default, define only those needing overrides
     # Accessors access the storage in %{$_[0][0]};
-    # TIEHANDLE should return an array reference with the first element being
+    # TIEHASH should return an array reference with the first element being
     # the reference to the actual storage 
     sub DELETE { 
       $_[0][1]->('del', $_[0][0], $_[1]); # Call the report writer
-      delete $_[0][0]->{$_[1]};		  #  $_[0]->SUPER::DELETE($_[1]) }
+      delete $_[0][0]->{$_[1]};		  #  $_[0]->SUPER::DELETE($_[1])
+    }
 
 
     package main;
@@ -104,13 +105,20 @@ Delete the key I<key> from the tied hash I<this>.
 
 Clear all values from the tied hash I<this>.
 
+=item SCALAR this
+
+Returns what evaluating the hash in scalar context yields.
+
+B<Tie::Hash> does not implement this method (but B<Tie::StdHash>
+and B<Tie::ExtraHash> do).
+
 =back
 
 =head1 Inheriting from B<Tie::StdHash>
 
 The accessor methods assume that the actual storage for the data in the tied
 hash is in the hash referenced by C<tied(%tiedhash)>.  Thus overwritten
-C<TIEHANDLE> method should return a hash reference, and the remaining methods
+C<TIEHASH> method should return a hash reference, and the remaining methods
 should operate on the hash referenced by the first argument:
 
   package ReportHash;
@@ -130,8 +138,8 @@ should operate on the hash referenced by the first argument:
 =head1 Inheriting from B<Tie::ExtraHash>
 
 The accessor methods assume that the actual storage for the data in the tied
-hash is in the hash referenced by C<(tied(%tiedhash))[0]>.  Thus overwritten
-C<TIEHANDLE> method should return an array reference with the first
+hash is in the hash referenced by C<(tied(%tiedhash))-E<gt>[0]>.  Thus overwritten
+C<TIEHASH> method should return an array reference with the first
 element being a hash reference, and the remaining methods should operate on the
 hash C<< %{ $_[0]->[0] } >>:
 
@@ -149,21 +157,24 @@ hash C<< %{ $_[0]->[0] } >>:
     $_[0][0]{$_[1]} = $_[2]
   }
 
-The default C<TIEHANDLE> method stores "extra" arguments to tie() starting
+The default C<TIEHASH> method stores "extra" arguments to tie() starting
 from offset 1 in the array referenced by C<tied(%tiedhash)>; this is the
 same storage algorithm as in TIEHASH subroutine above.  Hence, a typical
 package inheriting from B<Tie::ExtraHash> does not need to overwrite this
 method.
 
-=head1 C<UNTIE> and C<DESTROY>
+=head1 C<SCALAR>, C<UNTIE> and C<DESTROY>
 
 The methods C<UNTIE> and C<DESTROY> are not defined in B<Tie::Hash>,
 B<Tie::StdHash>, or B<Tie::ExtraHash>.  Tied hashes do not require
-presense of these methods, but if defined, the methods will be called in
+presence of these methods, but if defined, the methods will be called in
 proper time, see L<perltie>.
 
+C<SCALAR> is only defined in B<Tie::StdHash> and B<Tie::ExtraHash>.
+
 If needed, these methods should be defined by the package inheriting from
-B<Tie::Hash>, B<Tie::StdHash>, or B<Tie::ExtraHash>.
+B<Tie::Hash>, B<Tie::StdHash>, or B<Tie::ExtraHash>. See L<pertie/"SCALAR">
+to find out what happens when C<SCALAR> does not exist.
 
 =head1 MORE INFORMATION
 
@@ -229,6 +240,7 @@ sub NEXTKEY  { each %{$_[0]} }
 sub EXISTS   { exists $_[0]->{$_[1]} }
 sub DELETE   { delete $_[0]->{$_[1]} }
 sub CLEAR    { %{$_[0]} = () }
+sub SCALAR   { scalar %{$_[0]} }
 
 package Tie::ExtraHash;
 
@@ -240,5 +252,6 @@ sub NEXTKEY  { each %{$_[0][0]} }
 sub EXISTS   { exists $_[0][0]->{$_[1]} }
 sub DELETE   { delete $_[0][0]->{$_[1]} }
 sub CLEAR    { %{$_[0][0]} = () }
+sub SCALAR   { scalar %{$_[0][0]} }
 
 1;