This is 0.27

[perl/modules/Variable-Magic.git] / README

diff --git a/README b/README
index 78c47b386653adea52d5c21effacf4e8da3a8169..d5004fc0fd7ac68598b453f4a6961dca6b4b84dd 100644 (file)
--- a/README
+++ b/README
@@ -2,7 +2,7 @@ NAME
     Variable::Magic - Associate user-defined magic to variables from Perl.
 
 VERSION
-    Version 0.21_01
+    Version 0.27
 
 SYNOPSIS
         use Variable::Magic qw/wizard cast dispell/;
@@ -16,11 +16,27 @@ SYNOPSIS
 
 DESCRIPTION
     Magic is Perl way of enhancing objects. This mechanism let the user add
-    extra data to any variable and overload syntaxical operations (such as
+    extra data to any variable and hook syntaxical operations (such as
     access, assignation or destruction) that can be applied to it. With this
     module, you can add your own magic to any variable without the pain of
     the C API.
 
+    Magic differs from tieing and overloading in several ways :
+
+    *   Magic isn't copied on assignation (as for blessed references) : you
+        attach it to variables, not values.
+
+    *   It doesn't replace the original semantics : magic callbacks trigger
+        before the original action take place, and can't prevent it to
+        happen.
+
+    *   It's mostly invisible at the Perl level : magical and non-magical
+        variables cannot be distinguished with "ref", "reftype" or another
+        trick.
+
+    *   It's notably faster, since perl's way of handling magic is lighter
+        by nature, and there's no need for any method resolution.
+
     The operations that can be overloaded are :
 
     *   "get"
@@ -107,6 +123,12 @@ PERL MAGIC HISTORY
 
         *p14416* : 'copy' and 'dup' magic.
 
+    *   5.8.9
+
+        *p28160* : Integration of *p25854* (see below).
+
+        *p32542* : Integration of *p31473* (see below).
+
     *   5.9.3
 
         *p25854* : 'len' magic is no longer called when pushing an element
@@ -132,6 +154,10 @@ PERL MAGIC HISTORY
         *p32969* : 'len' magic is no longer invoked when calling "length"
         with a magical scalar.
 
+        *p34908* : 'len' magic is no longer called when pushing / unshifting
+        an element into a magical array in void context. The "push" part was
+        already covered by *p25854*.
+
 CONSTANTS
   "SIG_MIN"
     The minimum integer used as a signature for user-defined magic.
@@ -159,6 +185,10 @@ CONSTANTS
     True for perls that don't call 'len' magic when you push an element in a
     magical array.
 
+  "VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID"
+    True for perls that don't call 'len' magic when you unshift in void
+    context an element in a magical array.
+
   "VMG_COMPAT_ARRAY_UNDEF_CLEAR"
     True for perls that call 'clear' magic when undefining magical arrays.
 
@@ -223,6 +253,10 @@ FUNCTIONS
         (for example) cast magic on it. "copy" magic also receives the
         current element (i.e. the value) in $_[3].
 
+        All the callbacks are expected to return an integer, which is passed
+        straight to the perl magic API. However, only the return value of
+        the "len" callback currently holds a meaning.
+
         # A simple scalar tracer
         my $wiz = wizard get  => sub { print STDERR "got ${$_[0]}\n" },
                          set  => sub { print STDERR "set to ${$_[0]}\n" },
@@ -301,6 +335,8 @@ CAVEATS
     this destructor won't be called because the wizard will be destroyed
     first.
 
+    Using "get" and "clear" magics on hashes may cause segfaults.
+
 DEPENDENCIES
     perl 5.7.3.
 
@@ -324,8 +360,7 @@ SEE ALSO
 AUTHOR
     Vincent Pit, "<perl at profvince.com>", <http://www.profvince.com>.
 
-    You can contact me by mail or on #perl @ FreeNode (vincent or
-    Prof_Vince).
+    You can contact me by mail or on "irc.perl.org" (vincent).
 
 BUGS
     Please report any bugs or feature requests to "bug-variable-magic at
@@ -343,7 +378,7 @@ SUPPORT
     <http://www.profvince.com/perl/cover/Variable-Magic>.
 
 COPYRIGHT & LICENSE
-    Copyright 2007-2008 Vincent Pit, all rights reserved.
+    Copyright 2007-2009 Vincent Pit, all rights reserved.
 
     This program is free software; you can redistribute it and/or modify it
     under the same terms as Perl itself.