Importing Variable-Magic-0.07_01.tar.gz

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

diff --git a/README b/README
index 541b09da0daa68af9a14683aa6da0137ba1b4c0f..a626da01eb6c5a454204c4eb90abea31e75b80ca 100644 (file)
--- a/README
+++ b/README
@@ -2,12 +2,12 @@ NAME
     Variable::Magic - Associate user-defined magic to variables from Perl.
 
 VERSION
     Variable::Magic - Associate user-defined magic to variables from Perl.
 
 VERSION

-    Version 0.01
+    Version 0.07_01

 
 SYNOPSIS
         use Variable::Magic qw/wizard cast dispell/;
 
 
 SYNOPSIS
         use Variable::Magic qw/wizard cast dispell/;
 

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

         my $a = 1;
         cast $a, $wiz;
         $a = 2;          # "now set to 2!"
         my $a = 1;
         cast $a, $wiz;
         $a = 2;          # "now set to 2!"


@@ -41,8 +41,9 @@ DESCRIPTION
     "clear"
         This magic is invoked when the variable is reset, such as when an
         array is emptied. Please note that this is different from undefining
     "clear"
         This magic is invoked when the variable is reset, such as when an
         array is emptied. Please note that this is different from undefining

-        the variable, even though the magic is called when the reset is a
-        result of the undefine (e.g. for an array).
+        the variable, even though the magic is called when the clearing is a
+        result of the undefine (e.g. for an array, but actually a bug
+        prevent it to work before perl 5.9.5 - see the history).

 
     "free"
         This last one can be considered as an object destructor. It happens
 
     "free"
         This last one can be considered as an object destructor. It happens


@@ -53,6 +54,18 @@ DESCRIPTION
     an unique numerical signature is attached to each kind of magic (i.e.
     each set of callbacks for magic operations).
 
     an unique numerical signature is attached to each kind of magic (i.e.
     each set of callbacks for magic operations).
 

+PERL MAGIC HISTORY
+    The places where magic is invoked have changed a bit through perl
+    history. Here's a little list of the most recent ones.
+
+  5.9.3
+    'len' magic is no longer called when pushing an element into a magic
+    array.
+
+  5.9.5
+    'clear' magic wasn't invoked when undefining an array. The bug is fixed
+    as of this version.
+

 CONSTANTS
   "SIG_MIN"
     The minimum integer used as a signature for user-defined magic.
 CONSTANTS
   "SIG_MIN"
     The minimum integer used as a signature for user-defined magic.


@@ -63,6 +76,15 @@ CONSTANTS
   "SIG_NBR"
         SIG_NBR = SIG_MAX - SIG_MIN + 1
 
   "SIG_NBR"
         SIG_NBR = SIG_MAX - SIG_MIN + 1
 

+  "MGf_COPY"
+    True iff the 'copy' magic is available.
+
+  "MGf_DUP"
+    True iff the 'dup' magic is available.
+
+  "MGf_LOCAL"
+    True iff the 'local' magic is available.
+

 FUNCTIONS
   "wizard"
         wizard sig => .., data => ..., get => .., set => .., len => .., clear => .., free => ..
 FUNCTIONS
   "wizard"
         wizard sig => .., data => ..., get => .., set => .., len => .., clear => .., free => ..


@@ -73,26 +95,29 @@ FUNCTIONS
 
     'sig'
         The numerical signature. If not specified or undefined, a random
 
     'sig'
         The numerical signature. If not specified or undefined, a random

-        signature is generated.
+        signature is generated. If the signature matches an already defined
+        magic, then the existant magic object is returned.

 
     'data'
 
     'data'

-        A code reference to a private data constructor. It will be called
-        each time this magic is cast on a variable, and the scalar returned
-        will be used as private data storage for it.
+        A code reference to a private data constructor. It is called each
+        time this magic is cast on a variable, and the scalar returned is
+        used as private data storage for it. $_[0] is a reference to the
+        magic object and @_[1 .. @_-1] are all extra arguments that were
+        passed to "cast".

 
     'get', 'set', 'len', 'clear' and 'free'
         Code references to corresponding magic callbacks. You don't have to
         specify all of them : the magic associated with undefined entries
 
     'get', 'set', 'len', 'clear' and 'free'
         Code references to corresponding magic callbacks. You don't have to
         specify all of them : the magic associated with undefined entries

-        simply won't be hooked. When the magic variable is an array or a
-        hash, $_[0] is a reference to it, but directly references it
-        otherwise. $_[1] is the private data (or "undef" when no private
-        data constructor was supplied). In the special case of "len" magic
-        and when the variable is an array, $_[2] contains its normal length.
+        simply won't be hooked. In those callbacks, $_[0] is a reference to
+        the magic object and $_[1] is the private data (or "undef" when no
+        private data constructor was supplied). In the special case of "len"
+        magic and when the variable is an array, $_[2] contains its normal
+        length.

 
         # A simple scalar tracer
 
         # 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" }

 
   "gensig"
     With this tool, you can manually generate random magic signature between
 
   "gensig"
     With this tool, you can manually generate random magic signature between


@@ -111,32 +136,41 @@ FUNCTIONS
         my $sig = getsig $wiz;
 
   "cast"
         my $sig = getsig $wiz;
 
   "cast"

-        cast [$@%&*]var, $wiz
+        cast [$@%&*]var, [$wiz|$sig], ...

 
     This function associates $wiz magic to the variable supplied, without
 
     This function associates $wiz magic to the variable supplied, without

-    overwriting any other kind of magic. It returns true on success or when
-    $wiz magic is already present, and false on error.
-
-        # Casts $wiz to $x
+    overwriting any other kind of magic. You can also supply the numeric
+    signature $sig instead of $wiz. It returns true on success or when $wiz
+    magic is already present, 0 on error, and "undef" when no magic
+    corresponds to the given signature (in case $sig was supplied). All
+    extra arguments specified after $wiz are passed to the private data
+    constructor.
+
+        # Casts $wiz onto $x. If $wiz isn't a signature, undef can't be returned.

         my $x;
         die 'error' unless cast $x, $wiz;
 
   "getdata"
         my $x;
         die 'error' unless cast $x, $wiz;
 
   "getdata"

-        getdata [$@%&*]var, $wiz
+        getdata [$@%&*]var, [$wiz|$sig]
+
+    This accessor fetches the private data associated with the magic $wiz
+    (or the signature $sig) in the variable. "undef" is returned when no
+    such magic or data is found, or when $sig does not represent a current
+    valid magic object.

 
 

-    This accessor fetches the private data associated with the magic $wiz in
-    the variable. "undef" is returned when no such magic or data is found.
+        # Get the attached data.
+        my $data = getdata $x, $wiz or die 'no such magic or magic has no data';

 
   "dispell"
 
   "dispell"

-        dispell [$@%&*]variable, $wiz
-        dispell [$@%&*]variable, $sig
+        dispell [$@%&*]variable, [$wiz|$sig]

 
     The exact opposite of "cast" : it dissociates $wiz magic from the
 
     The exact opposite of "cast" : it dissociates $wiz magic from the

-    variable. You can also pass the magic signature as the second argument.
-    True is returned on success, and false on error or when no magic
-    represented by $wiz could be found in the variable.
+    variable. You can also pass the magic signature $sig as the second
+    argument. True is returned on success, 0 on error or when no magic
+    represented by $wiz could be found in the variable, and "undef" when no
+    magic corresponds to the given signature (in case $sig was supplied).

 
 

-        # Dispell now
+        # Dispell now. If $wiz isn't a signature, undef can't be returned.

         die 'no such magic or error' unless dispell $x, $wiz;
 
 EXPORT
         die 'no such magic or error' unless dispell $x, $wiz;
 
 EXPORT


@@ -148,9 +182,11 @@ EXPORT
     on request. They are all exported by the tags ':consts' and ':all'.
 
 DEPENDENCIES
     on request. They are all exported by the tags ':consts' and ':all'.
 
 DEPENDENCIES

+    perl 5.7.3.
+

     Carp (standard since perl 5), XSLoader (standard since perl 5.006).
 
     Carp (standard since perl 5), XSLoader (standard since perl 5.006).
 

-    Tests use Symbol (standard since perl 5.002).
+    Glob tests need Symbol (standard since perl 5.002).

 
 SEE ALSO
     perlguts and perlapi for internal information about magic.
 
 SEE ALSO
     perlguts and perlapi for internal information about magic.


@@ -158,6 +194,8 @@ SEE ALSO
 AUTHOR
     Vincent Pit, "<perl at profvince.com>"
 
 AUTHOR
     Vincent Pit, "<perl at profvince.com>"
 

+    You can contact me by mail or on #perl @ FreeNode (Prof_Vince).
+

 BUGS
     Please report any bugs or feature requests to "bug-variable-magic at
     rt.cpan.org", or through the web interface at
 BUGS
     Please report any bugs or feature requests to "bug-variable-magic at
     rt.cpan.org", or through the web interface at