package Variable::Magic;
-use 5.007003;
+use 5.008;
use strict;
use warnings;
-use Carp qw/croak/;
-
=head1 NAME
Variable::Magic - Associate user-defined magic to variables from Perl.
=head1 VERSION
-Version 0.25
+Version 0.46
=cut
our $VERSION;
BEGIN {
- $VERSION = '0.25';
+ $VERSION = '0.46';
}
=head1 SYNOPSIS
- use Variable::Magic qw/wizard cast dispell/;
-
- my $wiz = wizard set => sub { print STDERR "now set to ${$_[0]}!\n" };
- my $a = 1;
- cast $a, $wiz;
- $a = 2; # "now set to 2!"
- dispell $a, $wiz;
- $a = 3 # (nothing)
+ use Variable::Magic qw<wizard cast VMG_OP_INFO_NAME>;
+
+ { # A variable tracer
+ my $wiz = wizard(
+ set => sub { print "now set to ${$_[0]}!\n" },
+ free => sub { print "destroyed!\n" },
+ );
+
+ my $a = 1;
+ cast $a, $wiz;
+ $a = 2; # "now set to 2!"
+ } # "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 %h = (_default => 0, apple => 2);
+ cast %h, $wiz, '_default';
+ print $h{banana}, "\n"; # "0" (there is no 'banana' key in %h)
+ $h{pear} = 1; # "key pear stored in helem"
+ }
=head1 DESCRIPTION
-Magic is Perl way of enhancing objects. This mechanism let the user add extra data to any variable and hook syntaxical operations (such as access, assignation or destruction) that can be applied to it. With this module, you can add your own magic to any variable without the pain of the C API.
+Magic is Perl's way of enhancing variables.
+This mechanism lets the user add extra data to any variable and hook syntactical operations (such as access, assignment or destruction) that can be applied to it.
+With this module, you can add your own magic to any variable without having to write a single line of XS.
+
+You'll realize that these magic variables look a lot like tied variables.
+It's not surprising, as tied variables are implemented as a special kind of magic, just like any 'irregular' Perl variable : scalars like C<$!>, C<$(> or C<$^W>, the C<%ENV> and C<%SIG> hashes, the C<@ISA> array, C<vec()> and C<substr()> lvalues, L<threads::shared> variables...
+They all share the same underlying C API, and this module gives you direct access to it.
-Magic differs from tieing and overloading in several ways :
+Still, the magic made available by this module differs from tieing and overloading in several ways :
=over 4
=item *
-Magic isn't copied on assignation (as for blessed references) : you attach it to variables, not values.
+It isn't copied on assignment.
+
+You attach it to variables, not values (as for blessed references).
=item *
-It doesn't replace the original semantics : magic callbacks trigger before the original action take place, and can't prevent it to happen.
+It doesn't replace the original semantics.
+
+Magic callbacks usually get triggered before the original action takes place, and can't prevent it from happening.
+This also makes catching individual events easier than with C<tie>, where you have to provide fallbacks methods for all actions by usually inheriting from the correct C<Tie::Std*> class and overriding individual methods in your own class.
+
+=item *
+
+It's type-agnostic.
+
+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.
=item *
-It's mostly invisible at the Perl level : magical and non-magical variables cannot be distinguished with C<ref>, C<reftype> or another trick.
+It's mostly invisible at the Perl level.
+
+Magical and non-magical variables cannot be distinguished with C<ref>, C<tied> or another trick.
=item *
-It's notably faster, since perl's way of handling magic is lighter by nature, and there's no need for any method resolution.
+It's notably faster.
+
+Mainly because perl's way of handling magic is lighter by nature, and because there's no need for any method resolution.
+Also, since you don't have to reimplement all the variable semantics, you only pay for what you actually use.
=back
C<get>
-This magic is invoked when the variable is evaluated (does not include array/hash subscripts and slices).
+This magic is invoked when the variable is evaluated.
+It is never called for arrays and hashes.
=item *
C<set>
-This one is triggered each time the value of the variable changes (includes array/hash subscripts and slices).
+This one is triggered each time the value of the variable changes.
+It is called for array subscripts and slices, but never for hashes.
=item *
C<len>
-This magic is a little special : it is called when the 'size' or the 'length' of the variable has to be known by Perl. Typically, it's the magic involved when an array is evaluated in scalar context, but also on array assignation and loops (C<for>, C<map> or C<grep>). The callback has then to return the length as an integer.
+This magic is a little special : it is called when the 'size' or the 'length' of the variable has to be known by Perl.
+Typically, it's the magic involved when an array is evaluated in scalar context, but also on array assignment and loops (C<for>, C<map> or C<grep>).
+The callback has then to return the length as an integer.
=item *
C<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 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 L<history|/PERL MAGIC HISTORY>).
+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 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 L<history|/PERL MAGIC HISTORY>).
=item *
C<free>
-This one can be considered as an object destructor. It happens when the variable goes out of scope (with the exception of global scope), but not when it is undefined.
+This one can be considered as an object destructor.
+It happens when the variable goes out of scope, but not when it is undefined.
=item *
C<copy>
-This magic only applies to tied arrays and hashes. It fires when you try to access or change their elements. It is available on your perl iff C<MGf_COPY> is true.
+This magic only applies to tied arrays and hashes.
+It fires when you try to access or change their elements.
+It is available on your perl iff C<MGf_COPY> is true.
=item *
C<dup>
-Invoked when the variable is cloned across threads. Currently not available.
+Invoked when the variable is cloned across threads.
+Currently not available.
=item *
C<local>
-When this magic is set on a variable, all subsequent localizations of the variable will trigger the callback. It is available on your perl iff C<MGf_LOCAL> is true.
+When this magic is set on a variable, all subsequent localizations of the variable will trigger the callback.
+It is available on your perl iff C<MGf_LOCAL> is true.
=back
-The following actions only apply to hashes and are available iff C<VMG_UVAR> is true. They are referred to as C<uvar> magics.
+The following actions only apply to hashes and are available iff L</VMG_UVAR> is true.
+They are referred to as C<uvar> magics.
=over 4
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).
+=head1 FUNCTIONS
-=head1 PERL MAGIC HISTORY
+=cut
+
+BEGIN {
+ require XSLoader;
+ XSLoader::load(__PACKAGE__, $VERSION);
+}
+
+=head2 C<wizard>
-The places where magic is invoked have changed a bit through perl history. Here's a little list of the most recent ones.
+ wizard(
+ data => sub { ... },
+ get => sub { my ($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 => $bool,
+ op_info => [ 0 | VMG_OP_INFO_NAME | VMG_OP_INFO_OBJECT ],
+ )
+
+This function creates a 'wizard', an opaque type that holds the magic information.
+It takes a list of keys / values as argument, whose keys can be :
=over 4
=item *
-B<5.6.x>
+C<data>
-I<p14416> : 'copy' and 'dup' magic.
+A code (or string) reference to a private data constructor.
+It is called each time this magic is cast on a variable, and the scalar returned is used as private data storage for it.
+C<$_[0]> is a reference to the magic object and C<@_[1 .. @_-1]> are all extra arguments that were passed to L</cast>.
=item *
-B<5.8.9>
+C<get>, C<set>, C<len>, C<clear>, C<free>, C<copy>, C<local>, C<fetch>, C<store>, C<exists> and C<delete>
-I<p28160> : Integration of I<p25854> (see below).
+Code (or string) references to the corresponding magic callbacks.
+You don't have to specify all of them : the magic associated with undefined entries simply won't be hooked.
+In those callbacks, C<$_[0]> is always a reference to the magic object and C<$_[1]> is always the private data (or C<undef> when no private data constructor was supplied).
-I<p32542> : Integration of I<p31473> (see below).
+Moreover, when you pass C<< op_info => $num >> to C<wizard>, the last element of C<@_> will be the current op name if C<$num == VMG_OP_INFO_NAME> and a C<B::OP> object representing the current op if C<$num == VMG_OP_INFO_OBJECT>.
+Both have a performance hit, but just getting the name is lighter than getting the op object.
+
+Other arguments are specific to the magic hooked :
+
+=over 8
=item *
-B<5.9.3>
+C<len>
-I<p25854> : 'len' magic is no longer called when pushing an element into a magic array.
+When the variable is an array or a scalar, C<$_[2]> contains the non-magical length.
+The callback can return the new scalar or array length to use, or C<undef> to default to the normal length.
-I<p26569> : 'local' magic.
+=item *
+
+C<copy>
+
+C<$_[2]> is a either a copy or an alias of the current key, which means that it is useless to try to change or cast magic on it.
+C<$_[3]> is an alias to the current element (i.e. the value).
=item *
-B<5.9.5>
+C<fetch>, C<store>, C<exists> and C<delete>
-I<p31064> : Meaningful 'uvar' magic.
+C<$_[2]> is an alias to the current key.
+Nothing prevents you from changing it, but be aware that there lurk dangerous side effects.
+For example, it may rightfully be readonly if the key was a bareword.
+You can get a copy instead by passing C<< copy_key => 1 >> to L</wizard>, which allows you to safely assign to C<$_[2]> in order to e.g. redirect the action to another key.
+This however has a little performance drawback because of the copy.
-I<p31473> : 'clear' magic wasn't invoked when undefining an array. The bug is fixed as of this version.
+=back
-=item *
+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 C<len> callback currently holds a meaning.
-B<5.10.0>
+=back
-Since C<PERL_MAGIC_uvar> is uppercased, C<hv_magic_check()> triggers 'copy' magic on hash stores for (non-tied) hashes that also have 'uvar' magic.
+Each callback can be specified as a code or a string reference, in which case the function denoted by the string will be used as the callback.
-=item *
+Note that C<free> callbacks are I<never> called during global destruction, as there's no way to ensure that the wizard and the C<free> callback weren't destroyed before the variable.
-B<5.11.x>
+Here's a simple usage example :
-I<p32969> : 'len' magic is no longer invoked when calling C<length> with a magical scalar.
+ # 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" },
+ );
-I<p34908> : 'len' magic is no longer called when pushing / unshifting an element into a magical array in void context. The C<push> part was already covered by I<p25854>.
+=cut
-=back
+sub wizard {
+ if (@_ % 2) {
+ require Carp;
+ Carp::croak('Wrong number of arguments for wizard()');
+ }
-=head1 CONSTANTS
+ my %opts = @_;
+
+ my @keys = qw<op_info data get set len clear free copy dup>;
+ push @keys, 'local' if MGf_LOCAL;
+ push @keys, qw<fetch store exists delete copy_key> if VMG_UVAR;
+
+ my ($wiz, $err);
+ {
+ local $@;
+ $wiz = eval { _wizard(map $opts{$_}, @keys) };
+ $err = $@;
+ }
+ if ($err) {
+ $err =~ s/\sat\s+.*?\n//;
+ require Carp;
+ Carp::croak($err);
+ }
+
+ return $wiz;
+}
+
+=head2 C<cast>
+
+ cast [$@%&*]var, $wiz, ...
-=head2 C<SIG_MIN>
+This function associates C<$wiz> magic to the variable supplied, without overwriting any other kind of magic.
+It returns true on success or when C<$wiz> magic is already present, and croaks on error.
+All extra arguments specified after C<$wiz> are passed to the private data constructor in C<@_[1 .. @_-1]>.
+If the variable isn't a hash, any C<uvar> callback of the wizard is safely ignored.
-The minimum integer used as a signature for user-defined magic.
+ # Casts $wiz onto $x, and pass '1' to the data constructor.
+ my $x;
+ cast $x, $wiz, 1;
-=head2 C<SIG_MAX>
+The C<var> argument can be an array or hash value.
+Magic for those behaves like for any other scalar, except that it is dispelled when the entry is deleted from the container.
+For example, if you want to call C<POSIX::tzset> each time the C<'TZ'> environment variable is changed in C<%ENV>, you can use :
-The maximum integer used as a signature for user-defined magic.
+ use POSIX;
+ cast $ENV{TZ}, wizard set => sub { POSIX::tzset(); () };
-=head2 C<SIG_NBR>
+If you want to overcome the possible deletion of the C<'TZ'> entry, you have no choice but to rely on C<store> uvar magic.
+
+=head2 C<getdata>
- SIG_NBR = SIG_MAX - SIG_MIN + 1
+ getdata [$@%&*]var, $wiz
+
+This accessor fetches the private data associated with the magic C<$wiz> in the variable.
+It croaks when C<$wiz> do not represent a valid magic object, and returns an empty list if no such magic is attached to the variable or when the wizard has no data constructor.
+
+ # Get the attached data, or undef if the wizard does not attach any.
+ my $data = getdata $x, $wiz;
+
+=head2 C<dispell>
+
+ dispell [$@%&*]variable, $wiz
+
+The exact opposite of L</cast> : it dissociates C<$wiz> magic from the variable.
+This function returns true on success, C<0> when no magic represented by C<$wiz> could be found in the variable, and croaks if the supplied wizard is invalid.
+
+ # Dispell now.
+ die 'no such magic in $x' unless dispell $x, $wiz;
+
+=head1 CONSTANTS
=head2 C<MGf_COPY>
=head2 C<VMG_UVAR>
When this constant is true, you can use the C<fetch,store,exists,delete> 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.
=head2 C<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 non-void context and hence is false.
+
+=head2 C<VMG_COMPAT_ARRAY_PUSH_NOLEN_VOID>
+
+True for perls that don't call 'len' magic when you push in void context an element in a magical array.
=head2 C<VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID>
True for perls that don't call 'len' magic when taking the C<length> of a magical scalar.
+=head2 C<VMG_COMPAT_GLOB_GET>
+
+True for perls that call 'get' magic for operations on globs.
+
=head2 C<VMG_PERL_PATCHLEVEL>
The perl patchlevel this module was built with, or C<0> for non-debugging perls.
True iff this module could have been built with thread-safety features enabled.
-=head1 FUNCTIONS
+=head2 C<VMG_FORKSAFE>
-=cut
+True iff this module could have been built with fork-safety features enabled.
+This will always be true except on Windows where it's false for perl 5.10.0 and below .
-BEGIN {
- require XSLoader;
- XSLoader::load(__PACKAGE__, $VERSION);
-}
+=head2 C<VMG_OP_INFO_NAME>
-=head2 C<wizard>
+Value to pass with C<op_info> to get the current op name in the magic callbacks.
- wizard sig => ...,
- data => sub { ... },
- get => sub { my ($ref, $data) = @_; ... },
- set => sub { my ($ref, $data) = @_; ... },
- len => sub { my ($ref, $data, $len) = @_; ... ; return $newlen; },
- clear => sub { my ($ref, $data) = @_; ... },
- free => sub { my ($ref, $data) = @_, ... },
- copy => sub { my ($ref, $data, $key, $elt) = @_; ... },
- local => sub { my ($ref, $data) = @_; ... },
- fetch => sub { my ($ref, $data, $key) = @_; ... },
- store => sub { my ($ref, $data, $key) = @_; ... },
- exists => sub { my ($ref, $data, $key) = @_; ... },
- delete => sub { my ($ref, $data, $key) = @_; ... }
-
-This function creates a 'wizard', an opaque type that holds the magic information. It takes a list of keys / values as argument, whose keys can be :
+=head2 C<VMG_OP_INFO_OBJECT>
-=over 4
+Value to pass with C<op_info> to get a C<B::OP> object representing the current op in the magic callbacks.
-=item *
+=head1 COOKBOOK
-C<sig>
+=head2 Associate an object to any perl variable
-The numerical signature. If not specified or undefined, a random signature is generated. If the signature matches an already defined magic, then the existant magic object is returned.
+This technique can be useful for passing user data through limited APIs.
+It is similar to using inside-out objects, but without the drawback of having to implement a complex destructor.
-=item *
+ {
+ package Magical::UserData;
-C<data>
+ use Variable::Magic qw<wizard cast getdata>;
-A code reference to a private data constructor. It is called each time this magic is cast on a variable, and the scalar returned is used as private data storage for it. C<$_[0]> is a reference to the magic object and C<@_[1 .. @_-1]> are all extra arguments that were passed to L</cast>.
+ my $wiz = wizard data => sub { \$_[1] };
-=item *
+ sub ud (\[$@%*&]) : lvalue {
+ my ($var) = @_;
+ my $data = &getdata($var, $wiz);
+ unless (defined $data) {
+ $data = \(my $slot);
+ &cast($var, $wiz, $slot)
+ or die "Couldn't cast UserData magic onto the variable";
+ }
+ $$data;
+ }
+ }
-C<get>, C<set>, C<len>, C<clear>, C<free>, C<copy>, C<local>, C<fetch>, C<store>, C<exists> and C<delete>
+ {
+ BEGIN { *ud = \&Magical::UserData::ud }
-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. In those callbacks, C<$_[0]> is always a reference to the magic object and C<$_[1]> is always the private data (or C<undef> when no private data constructor was supplied). In the special case of C<len> magic and when the variable is an array, C<$_[2]> contains its normal length. C<$_[2]> is the current key in C<copy>, C<fetch>, C<store>, C<exists> and C<delete> callbacks, although for C<copy> it may just be a copy of the actual key so it's useless to (for example) cast magic on it. C<copy> magic also receives the current element (i.e. the value) in C<$_[3]>.
+ my $cb;
+ $cb = sub { print 'Hello, ', ud(&$cb), "!\n" };
-=back
+ ud(&$cb) = 'world';
+ $cb->(); # Hello, world!
+ }
- # 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" }
+=head2 Recursively cast magic on datastructures
-=cut
+C<cast> can be called from any magical callback, and in particular from C<data>.
+This allows you to recursively cast magic on datastructures :
-sub wizard {
- croak 'Wrong number of arguments for wizard()' if @_ % 2;
- my %opts = @_;
- my @cbs = qw/sig data get set len clear free/;
- push @cbs, 'copy' if MGf_COPY;
- push @cbs, 'dup' if MGf_DUP;
- push @cbs, 'local' if MGf_LOCAL;
- push @cbs, qw/fetch store exists delete/ if VMG_UVAR;
- my $ret = eval { _wizard(map $opts{$_}, @cbs) };
- if (my $err = $@) {
- $err =~ s/\sat\s+.*?\n//;
- croak $err;
- }
- return $ret;
-}
+ my $wiz;
+ $wiz = wizard data => sub {
+ my ($var, $depth) = @_;
+ $depth ||= 0;
+ my $r = ref $var;
+ if ($r eq 'ARRAY') {
+ &cast((ref() ? $_ : \$_), $wiz, $depth + 1) for @$var;
+ } elsif ($r eq 'HASH') {
+ &cast((ref() ? $_ : \$_), $wiz, $depth + 1) for values %$var;
+ }
+ return $depth;
+ },
+ free => sub {
+ my ($var, $depth) = @_;
+ my $r = ref $var;
+ print "free $r at depth $depth\n";
+ ();
+ };
-=head2 C<gensig>
+ {
+ my %h = (
+ a => [ 1, 2 ],
+ b => { c => 3 }
+ );
+ cast %h, $wiz;
+ }
-With this tool, you can manually generate random magic signature between SIG_MIN and SIG_MAX inclusive. That's the way L</wizard> creates them when no signature is supplied.
+When C<%h> goes out of scope, this will print something among the lines of :
- # Generate a signature
- my $sig = gensig;
+ free HASH at depth 0
+ free HASH at depth 1
+ free SCALAR at depth 2
+ free ARRAY at depth 1
+ free SCALAR at depth 3
+ free SCALAR at depth 3
-=head2 C<getsig>
+Of course, this example does nothing with the values that are added after the C<cast>.
- getsig $wiz
+=head1 PERL MAGIC HISTORY
-This accessor returns the magic signature of this wizard.
+The places where magic is invoked have changed a bit through perl history.
+Here's a little list of the most recent ones.
- # Get $wiz signature
- my $sig = getsig $wiz;
+=over 4
-=head2 C<cast>
+=item *
- cast [$@%&*]var, [$wiz|$sig], ...
+B<5.6.x>
-This function associates C<$wiz> magic to the variable supplied, without overwriting any other kind of magic. You can also supply the numeric signature C<$sig> instead of C<$wiz>. It returns true on success or when C<$wiz> magic is already present, C<0> on error, and C<undef> when no magic corresponds to the given signature (in case C<$sig> was supplied). All extra arguments specified after C<$wiz> are passed to the private data constructor. If the variable isn't a hash, any C<uvar> callback of the wizard is safely ignored.
+I<p14416> : 'copy' and 'dup' magic.
- # Casts $wiz onto $x. If $wiz isn't a signature, undef can't be returned.
- my $x;
- die 'error' unless cast $x, $wiz;
+=item *
-=head2 C<getdata>
+B<5.8.9>
- getdata [$@%&*]var, [$wiz|$sig]
+I<p28160> : Integration of I<p25854> (see below).
-This accessor fetches the private data associated with the magic C<$wiz> (or the signature C<$sig>) in the variable. C<undef> is returned when no such magic or data is found, or when C<$sig> does not represent a current valid magic object.
+I<p32542> : Integration of I<p31473> (see below).
- # Get the attached data.
- my $data = getdata $x, $wiz or die 'no such magic or magic has no data';
+=item *
-=head2 C<dispell>
+B<5.9.3>
- dispell [$@%&*]variable, [$wiz|$sig]
+I<p25854> : 'len' magic is no longer called when pushing an element into a magic array.
-The exact opposite of L</cast> : it dissociates C<$wiz> magic from the variable. You can also pass the magic signature C<$sig> as the second argument. True is returned on success, C<0> on error or when no magic represented by C<$wiz> could be found in the variable, and C<undef> when no magic corresponds to the given signature (in case C<$sig> was supplied).
+I<p26569> : 'local' magic.
- # Dispell now. If $wiz isn't a signature, undef can't be returned.
- die 'no such magic or error' unless dispell $x, $wiz;
+=item *
+
+B<5.9.5>
+
+I<p31064> : Meaningful 'uvar' magic.
+
+I<p31473> : 'clear' magic wasn't invoked when undefining an array.
+The bug is fixed as of this version.
+
+=item *
+
+B<5.10.0>
+
+Since C<PERL_MAGIC_uvar> is uppercased, C<hv_magic_check()> triggers 'copy' magic on hash stores for (non-tied) hashes that also have 'uvar' magic.
+
+=item *
+
+B<5.11.x>
+
+I<p32969> : 'len' magic is no longer invoked when calling C<length> with a magical scalar.
+
+I<p34908> : 'len' magic is no longer called when pushing / unshifting an element into a magical array in void context.
+The C<push> part was already covered by I<p25854>.
+
+I<g9cdcb38b> : 'len' magic is called again when pushing into a magical array in non-void context.
+
+=back
=head1 EXPORT
-The functions L</wizard>, L</gensig>, L</getsig>, L</cast>, L</getdata> and L</dispell> are only exported on request. All of them are exported by the tags C<':funcs'> and C<':all'>.
+The functions L</wizard>, L</cast>, L</getdata> and L</dispell> are only exported on request.
+All of them are exported by the tags C<':funcs'> and C<':all'>.
-The constants L</SIG_MIN>, L</SIG_MAX>, L</SIG_NBR>, L</MGf_COPY>, L</MGf_DUP>, L</MGf_LOCAL> and L</VMG_UVAR> are also only exported on request. They are all exported by the tags C<':consts'> and C<':all'>.
+All the constants are also only exported on request, either individually or by the tags C<':consts'> and C<':all'>.
=cut
-use base qw/Exporter/;
+use base qw<Exporter>;
our @EXPORT = ();
our %EXPORT_TAGS = (
- 'funcs' => [ qw/wizard gensig getsig cast getdata dispell/ ],
- 'consts' => [ qw/SIG_MIN SIG_MAX SIG_NBR MGf_COPY MGf_DUP MGf_LOCAL VMG_UVAR/,
- qw/VMG_COMPAT_ARRAY_PUSH_NOLEN VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID VMG_COMPAT_ARRAY_UNDEF_CLEAR/,
- qw/VMG_COMPAT_SCALAR_LENGTH_NOLEN/,
- qw/VMG_PERL_PATCHLEVEL/,
- qw/VMG_THREADSAFE/ ]
+ 'funcs' => [ qw<wizard cast getdata dispell> ],
+ 'consts' => [ qw<
+ MGf_COPY MGf_DUP MGf_LOCAL VMG_UVAR
+ VMG_COMPAT_ARRAY_PUSH_NOLEN VMG_COMPAT_ARRAY_PUSH_NOLEN_VOID
+ VMG_COMPAT_ARRAY_UNSHIFT_NOLEN_VOID
+ VMG_COMPAT_ARRAY_UNDEF_CLEAR
+ VMG_COMPAT_SCALAR_LENGTH_NOLEN
+ VMG_COMPAT_GLOB_GET
+ VMG_PERL_PATCHLEVEL
+ VMG_THREADSAFE VMG_FORKSAFE
+ VMG_OP_INFO_NAME VMG_OP_INFO_OBJECT
+ > ],
);
our @EXPORT_OK = map { @$_ } values %EXPORT_TAGS;
$EXPORT_TAGS{'all'} = [ @EXPORT_OK ];
=head1 CAVEATS
-If you store a magic object in the private data slot, the magic won't be accessible by L</getdata> since it's not copied by assignation. The only way to address this would be to return a reference.
+If you store a magic object in the private data slot, the magic won't be accessible by L</getdata> since it's not copied by assignment.
+The only way to address this would be to return a reference.
If you define a wizard with a C<free> callback and cast it on itself, 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 L<perl> 5.10.0 (see L</VMG_UVAR>)
+
=head1 DEPENDENCIES
-L<perl> 5.7.3.
+L<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.
L<Carp> (standard since perl 5), L<XSLoader> (standard since perl 5.006).
=head1 COPYRIGHT & LICENSE
-Copyright 2007-2008 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.
projects / perl / modules / Variable-Magic.git / blobdiff