use warnings;
use metaclass;
-use Carp 'confess';
+use Moose::Meta::Attribute;
+use Moose::Util::TypeConstraints ();
+
+our $VERSION = '0.87';
+$VERSION = eval $VERSION;
+our $AUTHORITY = 'cpan:STEVAN';
+
+__PACKAGE__->meta->add_attribute('type_coercion_map' => (
+ reader => 'type_coercion_map',
+ default => sub { [] }
+));
+
+__PACKAGE__->meta->add_attribute(
+ Moose::Meta::Attribute->new('type_constraint' => (
+ reader => 'type_constraint',
+ weak_ref => 1
+ ))
+);
+
+# private accessor
+__PACKAGE__->meta->add_attribute('compiled_type_coercion' => (
+ accessor => '_compiled_type_coercion'
+));
+
+sub new {
+ my $class = shift;
+ my $self = Class::MOP::class_of($class)->new_object(@_);
+ $self->compile_type_coercion;
+ return $self;
+}
+
+sub compile_type_coercion {
+ my $self = shift;
+ my @coercion_map = @{$self->type_coercion_map};
+ my @coercions;
+ while (@coercion_map) {
+ my ($constraint_name, $action) = splice(@coercion_map, 0, 2);
+ my $type_constraint = ref $constraint_name ? $constraint_name : Moose::Util::TypeConstraints::find_or_parse_type_constraint($constraint_name);
+
+ unless ( defined $type_constraint ) {
+ require Moose;
+ Moose->throw_error("Could not find the type constraint ($constraint_name) to coerce from");
+ }
+
+ push @coercions => [
+ $type_constraint->_compiled_type_constraint,
+ $action
+ ];
+ }
+ $self->_compiled_type_coercion(sub {
+ my $thing = shift;
+ foreach my $coercion (@coercions) {
+ my ($constraint, $converter) = @$coercion;
+ if ($constraint->($thing)) {
+ local $_ = $thing;
+ return $converter->($thing);
+ }
+ }
+ return $thing;
+ });
+}
+
+sub has_coercion_for_type {
+ my ($self, $type_name) = @_;
+ my %coercion_map = @{$self->type_coercion_map};
+ exists $coercion_map{$type_name} ? 1 : 0;
+}
+
+sub add_type_coercions {
+ my ($self, @new_coercion_map) = @_;
+
+ my $coercion_map = $self->type_coercion_map;
+ my %has_coercion = @$coercion_map;
+
+ while (@new_coercion_map) {
+ my ($constraint_name, $action) = splice(@new_coercion_map, 0, 2);
+
+ if ( exists $has_coercion{$constraint_name} ) {
+ require Moose;
+ Moose->throw_error("A coercion action already exists for '$constraint_name'")
+ }
+
+ push @{$coercion_map} => ($constraint_name, $action);
+ }
+
+ # and re-compile ...
+ $self->compile_type_coercion;
+}
+
+sub coerce { $_[0]->_compiled_type_coercion->($_[1]) }
-our $VERSION = '0.01';
1;
=head1 NAME
-Moose::Meta::TypeCoercion - The Moose Type Coercion metaobject
-
-=head1 SYNOPSIS
+Moose::Meta::TypeCoercion - The Moose Type Coercion metaclass
=head1 DESCRIPTION
+A type coercion object is basically a mapping of one or more type
+constraints and the associated coercions subroutines.
+
+It's unlikely that you will need to instantiate an object of this
+class directly, as it's part of the deep internals of Moose.
+
=head1 METHODS
=over 4
-=item B<meta>
+=item B<< Moose::Meta::TypeCoercion->new(%options) >>
+
+Creates a new type coercion object, based on the options provided.
+
+=over 8
+
+=item * type_constraint
+
+This is the L<Moose::Meta::TypeConstraint> object for the type that is
+being coerced I<to>.
+
+=back
+
+=item B<< $coercion->type_coercion_map >>
+
+This returns the map of type constraints to coercions as an array
+reference. The values of the array alternate between type names and
+subroutine references which implement the coercion.
+
+The value is an array reference because coercions are tried in the
+order they are added.
+
+=item B<< $coercion->type_constraint >>
+
+This returns the L<Moose::Meta::TypeConstraint> that was passed to the
+constructor.
+
+=item B<< $coercion->has_coercion_for_type($type_name) >>
+
+Returns true if the coercion can coerce the named type.
+
+=item B<< $coercion->add_type_coercions( $type_name => $sub, ... ) >>
+
+This method takes a list of type names and subroutine references. If
+the coercion already has a mapping for a given type, it throws an
+exception.
+
+Coercions are actually
+
+=item B<< $coercion->coerce($value) >>
+
+This method takes a value and applies the first valid coercion it
+finds.
+
+This means that if the value could belong to more than type in the
+coercion object, the first coercion added is used.
+
+=item B<< Moose::Meta::TypeCoercion->meta >>
+
+This will return a L<Class::MOP::Class> instance for this class.
=back
=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.
=head1 COPYRIGHT AND LICENSE
-Copyright 2006 by Infinity Interactive, Inc.
+Copyright 2006-2009 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.
+it under the same terms as Perl itself.
-=cut
\ No newline at end of file
+=cut
projects / gitmo/Moose.git / blobdiff