1 package Moose::Meta::TypeConstraint::Parameterizable;
8 $VERSION = eval $VERSION;
9 our $AUTHORITY = 'cpan:STEVAN';
11 use base 'Moose::Meta::TypeConstraint';
12 use Moose::Meta::TypeConstraint::Parameterized;
13 use Moose::Util::TypeConstraints ();
15 __PACKAGE__->meta->add_attribute('constraint_generator' => (
16 accessor => 'constraint_generator',
17 predicate => 'has_constraint_generator',
20 sub generate_constraint_for {
21 my ($self, $type) = @_;
23 return unless $self->has_constraint_generator;
25 return $self->constraint_generator->($type->type_parameter)
26 if $type->is_subtype_of($self->name);
28 return $self->_can_coerce_constraint_from($type)
29 if $self->has_coercion
30 && $self->coercion->has_coercion_for_type($type->parent->name);
35 sub _can_coerce_constraint_from {
36 my ($self, $type) = @_;
37 my $coercion = $self->coercion;
38 my $constraint = $self->constraint_generator->($type->type_parameter);
40 local $_ = $coercion->coerce($_);
45 sub _parse_type_parameter {
46 my ($self, $type_parameter) = @_;
47 return Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($type_parameter);
51 my ($self, $type_parameter) = @_;
53 my $contained_tc = $self->_parse_type_parameter($type_parameter);
55 if ( $contained_tc->isa('Moose::Meta::TypeConstraint') ) {
56 my $tc_name = $self->name . '[' . $contained_tc->name . ']';
57 return Moose::Meta::TypeConstraint::Parameterized->new(
60 type_parameter => $contained_tc,
64 Moose->throw_error("The type parameter must be a Moose meta type");
78 Moose::Meta::TypeConstraint::Parameterizable - Higher Order type constraints for Moose
84 =item B<constraint_generator>
86 =item B<has_constraint_generator>
88 =item B<generate_constraint_for>
92 Given a single type constraint string, this method parses the string
93 and parameterizes the type based on the parsed string.
101 All complex software has bugs lurking in it, and this module is no
102 exception. If you find a bug please either email me, or add the bug
107 Stevan Little E<lt>stevan@iinteractive.comE<gt>
109 =head1 COPYRIGHT AND LICENSE
111 Copyright 2006-2008 by Infinity Interactive, Inc.
113 L<http://www.iinteractive.com>
115 This library is free software; you can redistribute it and/or modify
116 it under the same terms as Perl itself.