A swath of VERSION patches from Nicholas Clark.

[p5sagit/p5-mst-13.2.git] / lib / Hash / Util.pm

diff --git a/lib/Hash/Util.pm b/lib/Hash/Util.pm
index a1c9e64..658fd86 100644 (file)
--- a/lib/Hash/Util.pm
+++ b/lib/Hash/Util.pm
@@ -9,7 +9,7 @@ our @ISA        = qw(Exporter);
 our @EXPORT_OK  = qw(lock_keys unlock_keys lock_value unlock_value
                      lock_hash unlock_hash
                     );
-our $VERSION    = 0.04;
+our $VERSION    = 0.05;
 
 =head1 NAME
 
@@ -17,7 +17,7 @@ Hash::Util - A selection of general-utility hash subroutines
 
 =head1 SYNOPSIS
 
-  use Hash::Util qw(lock_keys   unlock_keys 
+  use Hash::Util qw(lock_keys   unlock_keys
                     lock_value  unlock_value
                     lock_hash   unlock_hash);
 
@@ -59,10 +59,13 @@ This is intended to largely replace the deprecated pseudo-hashes.
 
 Restricts the given %hash's set of keys to @keys.  If @keys is not
 given it restricts it to its current keyset.  No more keys can be
-added.  delete() and exists() will still work, but it does not effect
-the set of allowed keys.
+added. delete() and exists() will still work, but will not alter
+the set of allowed keys. B<Note>: the current implementation prevents
+the hash from being bless()ed while it is in a locked state. Any attempt
+to do so will raise an exception. Of course you can still bless()
+the hash before you call lock_keys() so this shouldn't be a problem.
 
-  unlock_keys(%hash;)
+  unlock_keys(%hash);
 
 Removes the restriction on the %hash's keyset.
 
@@ -94,22 +97,22 @@ sub lock_keys (\%;@) {
         Internals::SvREADONLY %$hash, 1;
     }
 
-    return undef;
+    return;
 }
 
 sub unlock_keys (\%) {
     my($hash) = shift;
 
     Internals::SvREADONLY %$hash, 0;
-    return undef;
+    return;
 }
 
 =item lock_value
 
 =item unlock_value
 
-  lock_key  (%hash, $key);
-  unlock_key(%hash, $key);
+  lock_value  (%hash, $key);
+  unlock_value(%hash, $key);
 
 Locks and unlocks an individual key of a hash.  The value of a locked
 key cannot be changed.
@@ -175,6 +178,15 @@ sub unlock_hash (\%) {
 
 =back
 
+=head1 CAVEATS
+
+Note that the trapping of the restricted operations is not atomic:
+for example
+
+    eval { %hash = (illegal_key => 1) }
+
+leaves the C<%hash> empty rather than with its original contents.
+
 =head1 AUTHOR
 
 Michael G Schwern <schwern@pobox.com> on top of code by Nick