When generating inlining code, distinguish between $default from calling $attr->defau...

[gitmo/Moose.git] / lib / Moose / Meta / TypeConstraint / Parameterizable.pm

diff --git a/lib/Moose/Meta/TypeConstraint/Parameterizable.pm b/lib/Moose/Meta/TypeConstraint/Parameterizable.pm
index 7b61ebb..aa8cf2d 100644 (file)
--- a/lib/Moose/Meta/TypeConstraint/Parameterizable.pm
+++ b/lib/Moose/Meta/TypeConstraint/Parameterizable.pm
@@ -4,31 +4,36 @@ use strict;
 use warnings;
 use metaclass;
 
-our $VERSION   = '0.57';
-$VERSION = eval $VERSION;
-our $AUTHORITY = 'cpan:STEVAN';
-
 use base 'Moose::Meta::TypeConstraint';
 use Moose::Meta::TypeConstraint::Parameterized;
 use Moose::Util::TypeConstraints ();
 
+use Carp 'confess';
+
 __PACKAGE__->meta->add_attribute('constraint_generator' => (
     accessor  => 'constraint_generator',
     predicate => 'has_constraint_generator',
+    Class::MOP::_definition_context(),
+));
+
+__PACKAGE__->meta->add_attribute('inline_generator' => (
+    accessor  => 'inline_generator',
+    predicate => 'has_inline_generator',
+    Class::MOP::_definition_context(),
 ));
 
 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;
 }
 
@@ -42,23 +47,49 @@ sub _can_coerce_constraint_from {
     };
 }
 
-sub parse_type_parameter {
+sub generate_inline_for {
+    my ($self, $type, $val) = @_;
+
+    confess "Can't generate an inline constraint for $type, since none "
+          . "was defined"
+        unless $self->has_inline_generator;
+
+    return '( do { ' . $self->inline_generator->( $self, $type, $val ) . ' } )';
+}
+
+sub _parse_type_parameter {
     my ($self, $type_parameter) = @_;
     return Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($type_parameter);
 }
 
 sub parameterize {
-    my ( $self, $contained_tc ) = @_;
+    my ($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,
+            name               => $tc_name,
+            parent             => $self,
+            type_parameter     => $contained_tc,
+            parameterized_from => $self,
         );
     }
     else {
+        require Moose;
         Moose->throw_error("The type parameter must be a Moose meta type");
     }
 }
@@ -66,54 +97,37 @@ sub parameterize {
 
 1;
 
+# ABSTRACT: Type constraints which can take a parameter (ArrayRef)
+
 __END__
 
 
 =pod
 
-=head1 NAME
-
-Moose::Meta::TypeConstraint::Parameterizable - Higher Order type constraints for Moose
-
-=head1 METHODS
-
-=over 4
-
-=item B<constraint_generator>
-
-=item B<has_constraint_generator>
+=head1 DESCRIPTION
 
-=item B<generate_constraint_for>
+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<parse_type_parameter>
+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.
 
-Given a string, convert it to a Perl structure.
+=head1 INHERITANCE
 
-=item B<parameterize>
+C<Moose::Meta::TypeConstraint::Parameterizable> is a subclass of
+L<Moose::Meta::TypeConstraint>.
 
-Given an array of type constraints, parameterize the current type constraint.
-
-=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 
-exception. If you find a bug please either email me, or add the bug
-to cpan-RT.
-
-=head1 AUTHOR
-
-Stevan Little E<lt>stevan@iinteractive.comE<gt>
-
-=head1 COPYRIGHT AND LICENSE
-
-Copyright 2006-2008 by Infinity Interactive, Inc.
-
-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.
+See L<Moose/BUGS> for details on reporting bugs.
 
 =cut