Move the sv length logic into a new vmg_sv_len() function

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

diff --git a/README b/README
index 98026bb4bc4e64d5d0c287d997d9bb8be06564a2..9ab46cb6d154c85298d63fa7a50c9afb64cbef46 100644 (file)
--- a/README
+++ b/README
@@ -2,14 +2,16 @@ NAME
     Variable::Magic - Associate user-defined magic to variables from Perl.
 
 VERSION
     Variable::Magic - Associate user-defined magic to variables from Perl.
 
 VERSION

-    Version 0.44
+    Version 0.47

 
 SYNOPSIS
 
 SYNOPSIS

-        use Variable::Magic qw/wizard cast VMG_OP_INFO_NAME/;
+        use Variable::Magic qw<wizard cast VMG_OP_INFO_NAME>;

 
         { # A variable tracer
 
         { # A variable tracer

-         my $wiz = wizard set  => sub { print "now set to ${$_[0]}!\n" },
-                          free => sub { print "destroyed!\n" };
+         my $wiz = wizard(
+          set  => sub { print "now set to ${$_[0]}!\n" },
+          free => sub { print "destroyed!\n" },
+         );

 
          my $a = 1;
          cast $a, $wiz;
 
          my $a = 1;
          cast $a, $wiz;


@@ -17,15 +19,17 @@ SYNOPSIS
         }               # "destroyed!"
 
         { # A hash with a default value
         }               # "destroyed!"
 
         { # A hash with a default value

-         my $wiz = wizard data     => sub { $_[1] },
-                          fetch    => sub { $_[2] = $_[1] unless exists $_[0]->{$_[2]}; () },
-                          store    => sub { print "key $_[2] stored in $_[-1]\n" },
-                          copy_key => 1,
-                          op_info  => VMG_OP_INFO_NAME;
+         my $wiz = wizard(
+          data     => sub { $_[1] },
+          fetch    => sub { $_[2] = $_[1] unless exists $_[0]->{$_[2]}; () },
+          store    => sub { print "key $_[2] stored in $_[-1]\n" },
+          copy_key => 1,
+          op_info  => VMG_OP_INFO_NAME,
+         );

 
          my %h = (_default => 0, apple => 2);
          cast %h, $wiz, '_default';
 
          my %h = (_default => 0, apple => 2);
          cast %h, $wiz, '_default';

-         print $h{banana}, "\n"; # "0", because the 'banana' key doesn't exist in %h
+         print $h{banana}, "\n"; # "0" (there is no 'banana' key in %h)

          $h{pear} = 1;           # "key pear stored in helem"
         }
 
          $h{pear} = 1;           # "key pear stored in helem"
         }
 


@@ -150,29 +154,26 @@ DESCRIPTION
     You can refer to the tests to have more insight of where the different
     magics are invoked.
 
     You can refer to the tests to have more insight of where the different
     magics are invoked.
 

-    To prevent any clash between different magics defined with this module,
-    an unique numerical signature is attached to each kind of magic (i.e.
-    each set of callbacks for magic operations). At the C level, magic
-    tokens owned by magic created by this module have their "mg->mg_private"
-    field set to 0x3891 or 0x3892, so please don't use these magic (sic)
-    numbers in other extensions.
-

 FUNCTIONS
   "wizard"
 FUNCTIONS
   "wizard"

-        wizard data     => sub { ... },
-               get      => sub { my ($ref, $data [, $op]) = @_; ... },
-               set      => sub { my ($ref, $data [, $op]) = @_; ... },
-               len      => sub { my ($ref, $data, $len [, $op]) = @_; ... ; return $newlen; },
-               clear    => sub { my ($ref, $data [, $op]) = @_; ... },
-               free     => sub { my ($ref, $data [, $op]) = @_, ... },
-               copy     => sub { my ($ref, $data, $key, $elt [, $op]) = @_; ... },
-               local    => sub { my ($ref, $data [, $op]) = @_; ... },
-               fetch    => sub { my ($ref, $data, $key [, $op]) = @_; ... },
-               store    => sub { my ($ref, $data, $key [, $op]) = @_; ... },
-               exists   => sub { my ($ref, $data, $key [, $op]) = @_; ... },
-               delete   => sub { my ($ref, $data, $key [, $op]) = @_; ... },
-               copy_key => $bool,
-               op_info  => [ 0 | VMG_OP_INFO_NAME | VMG_OP_INFO_OBJECT ]
+        wizard(
+         data     => sub { ... },
+         get      => sub { my ($ref, $data [, $op]) = @_; ... },
+         set      => sub { my ($ref, $data [, $op]) = @_; ... },
+         len      => sub {
+          my ($ref, $data, $len [, $op]) = @_; ... ; return $newlen
+         },
+         clear    => sub { my ($ref, $data [, $op]) = @_; ... },
+         free     => sub { my ($ref, $data [, $op]) = @_, ... },
+         copy     => sub { my ($ref, $data, $key, $elt [, $op]) = @_; ... },
+         local    => sub { my ($ref, $data [, $op]) = @_; ... },
+         fetch    => sub { my ($ref, $data, $key [, $op]) = @_; ... },
+         store    => sub { my ($ref, $data, $key [, $op]) = @_; ... },
+         exists   => sub { my ($ref, $data, $key [, $op]) = @_; ... },
+         delete   => sub { my ($ref, $data, $key [, $op]) = @_; ... },
+         copy_key => $bool,
+         op_info  => [ 0 | VMG_OP_INFO_NAME | VMG_OP_INFO_OBJECT ],
+        )

 
     This function creates a 'wizard', an opaque type that holds the magic
     information. It takes a list of keys / values as argument, whose keys
 
     This function creates a 'wizard', an opaque type that holds the magic
     information. It takes a list of keys / values as argument, whose keys


@@ -243,9 +244,11 @@ FUNCTIONS
     Here's a simple usage example :
 
         # A simple scalar tracer
     Here's a simple usage example :
 
         # A simple scalar tracer

-        my $wiz = wizard get  => sub { print STDERR "got ${$_[0]}\n" },
-                         set  => sub { print STDERR "set to ${$_[0]}\n" },
-                         free => sub { print STDERR "${$_[0]} was deleted\n" }
+        my $wiz = wizard(
+         get  => sub { print STDERR "got ${$_[0]}\n" },
+         set  => sub { print STDERR "set to ${$_[0]}\n" },
+         free => sub { print STDERR "${$_[0]} was deleted\n" },
+        );

 
   "cast"
         cast [$@%&*]var, $wiz, ...
 
   "cast"
         cast [$@%&*]var, $wiz, ...


@@ -307,7 +310,12 @@ CONSTANTS
 
   "VMG_UVAR"
     When this constant is true, you can use the "fetch,store,exists,delete"
 
   "VMG_UVAR"
     When this constant is true, you can use the "fetch,store,exists,delete"

-    callbacks on hashes.
+    callbacks on hashes. Initial VMG_UVAR capability was introduced in perl
+    5.9.5, with a fully functional implementation shipped with perl 5.10.0.
+
+  "VMG_COMPAT_SCALAR_LENGTH_NOLEN"
+    True for perls that don't call 'len' magic when taking the "length" of a
+    magical scalar.

 
   "VMG_COMPAT_ARRAY_PUSH_NOLEN"
     True for perls that don't call 'len' magic when you push an element in a
 
   "VMG_COMPAT_ARRAY_PUSH_NOLEN"
     True for perls that don't call 'len' magic when you push an element in a


@@ -325,9 +333,9 @@ CONSTANTS
   "VMG_COMPAT_ARRAY_UNDEF_CLEAR"
     True for perls that call 'clear' magic when undefining magical arrays.
 
   "VMG_COMPAT_ARRAY_UNDEF_CLEAR"
     True for perls that call 'clear' magic when undefining magical arrays.
 

-  "VMG_COMPAT_SCALAR_LENGTH_NOLEN"
-    True for perls that don't call 'len' magic when taking the "length" of a
-    magical scalar.
+  "VMG_COMPAT_HASH_DELETE_NOUVAR_VOID"
+    True for perls that don't call 'delete' uvar magic when you delete an
+    element from a hash in void context.

 
   "VMG_COMPAT_GLOB_GET"
     True for perls that call 'get' magic for operations on globs.
 
   "VMG_COMPAT_GLOB_GET"
     True for perls that call 'get' magic for operations on globs.


@@ -362,7 +370,7 @@ COOKBOOK
         {
          package Magical::UserData;
 
         {
          package Magical::UserData;
 

-         use Variable::Magic qw/wizard cast getdata/;
+         use Variable::Magic qw<wizard cast getdata>;

 
          my $wiz = wizard data => sub { \$_[1] };
 
 
          my $wiz = wizard data => sub { \$_[1] };
 


@@ -372,7 +380,7 @@ COOKBOOK
           unless (defined $data) {
            $data = \(my $slot);
            &cast($var, $wiz, $slot)
           unless (defined $data) {
            $data = \(my $slot);
            &cast($var, $wiz, $slot)

-                            or die "Couldn't cast UserData magic onto the variable";
+                     or die "Couldn't cast UserData magic onto the variable";

           }
           $$data;
          }
           }
           $$data;
          }


@@ -495,9 +503,15 @@ CAVEATS
     this destructor won't be called because the wizard will be destroyed
     first.
 
     this destructor won't be called because the wizard will be destroyed
     first.
 

+    In order to define magic on hash members, you need at least perl 5.10.0
+    (see "VMG_UVAR")
+

 DEPENDENCIES
     perl 5.8.
 
 DEPENDENCIES
     perl 5.8.
 

+    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 (standard since perl 5), XSLoader (standard since perl 5.006).
 
     Copy tests need Tie::Array (standard since perl 5.005) and Tie::Hash
     Carp (standard since perl 5), XSLoader (standard since perl 5.006).
 
     Copy tests need Tie::Array (standard since perl 5.005) and Tie::Hash


@@ -536,7 +550,7 @@ SUPPORT
     <http://www.profvince.com/perl/cover/Variable-Magic>.
 
 COPYRIGHT & LICENSE
     <http://www.profvince.com/perl/cover/Variable-Magic>.
 
 COPYRIGHT & LICENSE

-    Copyright 2007,2008,2009,2010 Vincent Pit, all rights reserved.
+    Copyright 2007,2008,2009,2010,2011 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.
 
     This program is free software; you can redistribute it and/or modify it
     under the same terms as Perl itself.