merging the immutable branch into trunk

[gitmo/Class-MOP.git] / lib / metaclass.pm

diff --git a/lib/metaclass.pm b/lib/metaclass.pm
index 917459f..e1bd16a 100644 (file)
--- a/lib/metaclass.pm
+++ b/lib/metaclass.pm
@@ -4,20 +4,27 @@ package metaclass;
 use strict;
 use warnings;
 
-use Carp 'confess';
+use Carp         'confess';
+use Scalar::Util 'blessed';
 
-our $VERSION = '0.01';
+our $VERSION   = '0.03';
+our $AUTHORITY = 'cpan:STEVAN';
 
 use Class::MOP;
 
 sub import {
     shift;
-    my $metaclass = shift || 'Class::MOP::Class';
-    my %options   = @_;
-    my $package   = caller();
-    
-    ($metaclass->isa('Class::MOP::Class'))
-        || confess 'The metaclass must be derived from Class::MOP::Class';
+    my $metaclass;
+    if (!defined($_[0]) || $_[0] =~ /^(attribute|method|instance)_metaclass/) {
+        $metaclass = 'Class::MOP::Class';
+    }
+    else {
+        $metaclass = shift;
+        ($metaclass->isa('Class::MOP::Class'))
+            || confess "The metaclass ($metaclass) must be derived from Class::MOP::Class";
+    }
+    my %options = @_;
+    my $package = caller();
     
     # create a meta object so we can install &meta
     my $meta = $metaclass->initialize($package => %options);
@@ -27,54 +34,10 @@ sub import {
         # since metaclass instances are 
         # singletons, this is not really a 
         # big deal anyway.
-        $metaclass->initialize($_[0] => %options)
+        $metaclass->initialize((blessed($_[0]) || $_[0]) => %options)
     });
 }
 
-=pod
-
-NOTES
-
-Okay, the metaclass constraint issue is a bit of a PITA.
-
-Especially in the context of MI, where we end up with an 
-explosion of metaclasses.
-
-SOOOO
-
-Instead of auto-composing metaclasses using inheritance 
-(which is problematic at best, and totally wrong at worst, 
-especially in the light of methods of Class::MOP::Class 
-which are overridden by subclasses (try to figure out how 
-LazyClass and InsideOutClass could be composed, it is not
-even possible)) we use a trait model.
-
-It will be similar to Class::Trait, except that there is 
-no such thing as a trait, a class isa trait and a trait 
-isa class, more like Scala really.
-
-This way we get several benefits:
-
-1) Classes can be composed like traits, and it Just Works.
-
-2) Metaclasses can be composed this way too :)
-
-3) When solving the metaclass constraint, we create an 
-   anon-metaclass, and compose the parent's metaclasses 
-   into it. This allows for conflict checking trait-style 
-   which should inform us of any issues right away.
-   
-Misc. Details:
-
-Class metaclasses must be composed, but so must any 
-associated Attribute and Method metaclasses. However, this 
-is not always relevant since I should be able to create a 
-class which has lazy attributes, and then create a subclass 
-of that class whose attributes are not lazy.
-
-
-=cut
-
 1;
 
 __END__
@@ -83,26 +46,46 @@ __END__
 
 =head1 NAME
 
-metaclass - a pragma for installing using Class::MOP metaclasses
+metaclass - a pragma for installing and using Class::MOP metaclasses
 
 =head1 SYNOPSIS
 
+  package MyClass;
+
+  # use Class::MOP::Class
+  use metaclass; 
+
+  # ... or use a custom metaclass
   use metaclass 'MyMetaClass';
   
+  # ... or use a custom metaclass  
+  # and custom attribute and method
+  # metaclasses
   use metaclass 'MyMetaClass' => (
-      ':attribute_metaclass' => 'MyAttributeMetaClass',
-      ':method_metaclass'    => 'MyMethodMetaClass',    
+      'attribute_metaclass' => 'MyAttributeMetaClass',
+      'method_metaclass'    => 'MyMethodMetaClass',    
+  );
+
+  # ... or just specify custom attribute
+  # and method classes, and Class::MOP::Class
+  # is the assumed metaclass
+  use metaclass (
+      'attribute_metaclass' => 'MyAttributeMetaClass',
+      'method_metaclass'    => 'MyMethodMetaClass',    
   );
 
 =head1 DESCRIPTION
 
 This is a pragma to make it easier to use a specific metaclass 
-and it's 
+and a set of custom attribute and method metaclasses. It also 
+installs a C<meta> method to your class as well. 
 
-=head1 AUTHOR
+=head1 AUTHORS
 
 Stevan Little E<lt>stevan@iinteractive.comE<gt>
 
+Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
+
 =head1 COPYRIGHT AND LICENSE
 
 Copyright 2006 by Infinity Interactive, Inc.
@@ -112,4 +95,4 @@ L<http://www.iinteractive.com>
 This library is free software; you can redistribute it and/or modify
 it under the same terms as Perl itself. 
 
-=cut
\ No newline at end of file
+=cut