This is 0.57

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

diff --git a/README b/README
index a7c09596b439f0f84ca65e2e4514f7c2b4a7a846..b10ea32ae8d3002cad4bf5842eddb182b843218d 100644 (file)
--- a/README
+++ b/README
@@ -2,7 +2,7 @@ NAME
     Variable::Magic - Associate user-defined magic to variables from Perl.
 
 VERSION
-    Version 0.51
+    Version 0.57
 
 SYNOPSIS
         use Variable::Magic qw<wizard cast VMG_OP_INFO_NAME>;
@@ -72,7 +72,7 @@ DESCRIPTION
 
         The same magic can be applied on scalars, arrays, hashes, subs or
         globs. But the same hook (see below for a list) may trigger
-        differently depending on the the type of the variable.
+        differently depending on the type of the variable.
 
     *   Magic is invisible at Perl level.
 
@@ -100,11 +100,19 @@ DESCRIPTION
 
     *   *len*
 
-        This magic only applies to scalars and arrays, and is triggered when
-        the 'size' or the 'length' of the variable has to be known by Perl.
-        This is typically the magic involved when an array is evaluated in
-        scalar context, but also on array assignment and loops ("for", "map"
-        or "grep"). The length is returned from the callback as an integer.
+        This magic only applies to arrays (though it used to also apply to
+        scalars), and is triggered when the 'size' or the 'length' of the
+        variable has to be known by Perl. This is typically the magic
+        involved when an array is evaluated in scalar context, but also on
+        array assignment and loops ("for", "map" or "grep"). The length is
+        returned from the callback as an integer.
+
+        Starting from perl 5.12, this magic is no longer called by the
+        "length" keyword, and starting from perl 5.17.4 it is also no longer
+        called for scalars in any situation, making this magic only
+        meaningful on arrays. You can use the constants
+        "VMG_COMPAT_SCALAR_LENGTH_NOLEN" and "VMG_COMPAT_SCALAR_NOLEN" to
+        see if this magic is available for scalars or not.
 
     *   *clear*
 
@@ -124,8 +132,13 @@ DESCRIPTION
 
     *   *copy*
 
-        This magic only applies to tied arrays and hashes, and fires when
-        you try to access or change their elements.
+        When applied to tied arrays and hashes, this magic fires when you
+        try to access or change their elements.
+
+        Starting from perl 5.17.0, it can also be applied to closure
+        prototypes, in which case the magic will be called when the
+        prototype is cloned. The "VMG_COMPAT_CODE_COPY_CLONE" constant is
+        true when your perl support this feature.
 
     *   *dup*
 
@@ -217,10 +230,15 @@ FUNCTIONS
 
         *       *copy*
 
-                $_[2] is a either an alias or a copy of the current key, and
-                $_[3] is an alias to the current element (i.e. the value).
-                Because $_[2] might be a copy, it is useless to try to
-                change it or cast magic on it.
+                When the variable for which the magic is invoked is an array
+                or an hash, $_[2] is a either an alias or a copy of the
+                current key, and $_[3] is an alias to the current element
+                (i.e. the value). Since $_[2] might be a copy, it is useless
+                to try to change it or cast magic on it.
+
+                Starting from perl 5.17.0, this magic can also be called for
+                code references. In this case, $_[2] is always "undef" and
+                $_[3] is a reference to the cloned anonymous subroutine.
 
         *       *fetch*, *store*, *exists* and *delete*
 
@@ -353,6 +371,10 @@ CONSTANTS
     True for perls that don't call *len* magic when taking the "length" of a
     magical scalar.
 
+  "VMG_COMPAT_SCALAR_NOLEN"
+    True for perls that don't call *len* magic on scalars. Implies
+    "VMG_COMPAT_SCALAR_LENGTH_NOLEN".
+
   "VMG_COMPAT_ARRAY_PUSH_NOLEN"
     True for perls that don't call *len* magic when you push an element in a
     magical array. Starting from perl 5.11.0, this only refers to pushes in
@@ -373,6 +395,10 @@ CONSTANTS
     True for perls that don't call *delete* magic when you delete an element
     from a hash in void context.
 
+  "VMG_COMPAT_CODE_COPY_CLONE"
+    True for perls that call *copy* magic when a magical closure prototype
+    is cloned.
+
   "VMG_COMPAT_GLOB_GET"
     True for perls that call *get* magic for operations on globs.
 
@@ -548,12 +574,7 @@ DEPENDENCIES
     A C compiler. This module may happen to build with a C++ compiler as
     well, but don't rely on it, as no guarantee is made in this regard.
 
-    Carp (core since perl 5), XSLoader (since 5.006).
-
-    Copy tests need Tie::Array (core since perl 5.005) and Tie::Hash (since
-    5.002). Some uvar tests need Hash::Util::FieldHash (since 5.009004).
-    Glob tests need Symbol (since 5.002). Threads tests need threads and
-    threads::shared (both since 5.007003).
+    Carp (core since perl 5), XSLoader (since 5.6.0).
 
 SEE ALSO
     perlguts and perlapi for internal information about magic.
@@ -581,8 +602,8 @@ SUPPORT
     <http://www.profvince.com/perl/cover/Variable-Magic>.
 
 COPYRIGHT & LICENSE
-    Copyright 2007,2008,2009,2010,2011,2012 Vincent Pit, all rights
-    reserved.
+    Copyright 2007,2008,2009,2010,2011,2012,2013,2014,2015 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.