X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FTypeConstraint%2FParameterizable.pm;h=cdb6469184f3d1088506f654d645e5f682ce5323;hb=eaf5a43ef108f6a9dce74c84afc25a892cffdfb1;hp=58734d7c044dba693c969bf10839a7a8dc7d8fe6;hpb=330dbb079ab3e4ff26fb694c232b9c86b2d19161;p=gitmo%2FMoose.git

diff --git a/lib/Moose/Meta/TypeConstraint/Parameterizable.pm b/lib/Moose/Meta/TypeConstraint/Parameterizable.pm
index 58734d7..cdb6469 100644
--- a/lib/Moose/Meta/TypeConstraint/Parameterizable.pm
+++ b/lib/Moose/Meta/TypeConstraint/Parameterizable.pm
@@ -4,10 +4,13 @@ use strict;
 use warnings;
 use metaclass;
 
-our $VERSION   = '0.55';
+our $VERSION   = '0.90';
+$VERSION = eval $VERSION;
 our $AUTHORITY = 'cpan:STEVAN';
 
 use base 'Moose::Meta::TypeConstraint';
+use Moose::Meta::TypeConstraint::Parameterized;
+use Moose::Util::TypeConstraints ();
 
 __PACKAGE__->meta->add_attribute('constraint_generator' => (
     accessor  => 'constraint_generator',
@@ -16,16 +19,16 @@ __PACKAGE__->meta->add_attribute('constraint_generator' => (
 
 sub generate_constraint_for {
     my ($self, $type) = @_;
-    
+
     return unless $self->has_constraint_generator;
-    
+
     return $self->constraint_generator->($type->type_parameter)
         if $type->is_subtype_of($self->name);
-        
+
     return $self->_can_coerce_constraint_from($type)
         if $self->has_coercion
         && $self->coercion->has_coercion_for_type($type->parent->name);
-        
+
     return;
 }
 
@@ -39,6 +42,42 @@ sub _can_coerce_constraint_from {
     };
 }
 
+sub _parse_type_parameter {
+    my ($self, $type_parameter) = @_;
+    return Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($type_parameter);
+}
+
+sub parameterize {
+    my ($self, $type_parameter) = @_;
+
+    my $contained_tc = $self->_parse_type_parameter($type_parameter);
+
+    ## The type parameter should be a subtype of the parent's type parameter
+    ## if there is one.
+
+    if(my $parent = $self->parent) {
+        if($parent->can('type_parameter')) {
+            unless ( $contained_tc->is_a_type_of($parent->type_parameter) ) {
+                require Moose;
+                Moose->throw_error("$type_parameter is not a subtype of ".$parent->type_parameter);
+            }
+        }
+    }
+
+    if ( $contained_tc->isa('Moose::Meta::TypeConstraint') ) {
+        my $tc_name = $self->name . '[' . $contained_tc->name . ']';
+        return Moose::Meta::TypeConstraint::Parameterized->new(
+            name           => $tc_name,
+            parent         => $self,
+            type_parameter => $contained_tc,
+        );
+    }
+    else {
+        require Moose;
+        Moose->throw_error("The type parameter must be a Moose meta type");
+    }
+}
+
 
 1;
 
@@ -49,25 +88,33 @@ __END__
 
 =head1 NAME
 
-Moose::Meta::TypeConstraint::Parameterizable - Higher Order type constraints for Moose
+Moose::Meta::TypeConstraint::Parameterizable - Type constraints which can take a parameter (ArrayRef)
 
-=head1 METHODS
+=head1 DESCRIPTION
 
-=over 4
+This class represents a parameterizable type constraint. This is a
+type constraint like C<ArrayRef> or C<HashRef>, that can be
+parameterized and made more specific by specifying a contained
+type. For example, instead of just an C<ArrayRef> of anything, you can
+specify that is an C<ArrayRef[Int]>.
 
-=item B<constraint_generator>
+A parameterizable constraint should not be used as an attribute type
+constraint. Instead, when parameterized it creates a
+L<Moose::Meta::TypeConstraint::Parameterized> which should be used.
 
-=item B<has_constraint_generator>
+=head1 INHERITANCE
 
-=item B<generate_constraint_for>
+C<Moose::Meta::TypeConstraint::Parameterizable> is a subclass of
+L<Moose::Meta::TypeConstraint>.
 
-=item B<meta>
+=head1 METHODS
 
-=back
+This class is intentionally not documented because the API is
+confusing and needs some work.
 
 =head1 BUGS
 
-All complex software has bugs lurking in it, and this module is no 
+All complex software has bugs lurking in it, and this module is no
 exception. If you find a bug please either email me, or add the bug
 to cpan-RT.
 
@@ -77,7 +124,7 @@ Stevan Little E<lt>stevan@iinteractive.comE<gt>
 
 =head1 COPYRIGHT AND LICENSE
 
-Copyright 2006-2008 by Infinity Interactive, Inc.
+Copyright 2006-2009 by Infinity Interactive, Inc.
 
 L<http://www.iinteractive.com>