perl - Moose structured types -

i'd create structured type in moose can used type moose attribute. example, i'd able create name attribute has own value , error attributes.

i therefore know best way of achieving this. have created working example defining simple moose class represent generic field object. has value , error attributes. have created moose class person object. has id , name attributes, both of of type field:

define generic field object:

package myapp::type::field; use moose; use namespace::autoclean;  has 'value' => ( => 'rw' );   has 'error' => ( => 'rw', isa => 'str' );  __package__->meta->make_immutable; 1; 

define person object uses field object:

package myapp::person; use moose; use namespace::autoclean; use myapp::type::field;  has 'id'   => ( => 'rw', isa => 'myapp::type::field' );     has 'name' => ( => 'rw', isa => 'myapp::type::field' );  __package__->meta->make_immutable; 1; 

do person object:

package myapp::test;  use moose; use namespace::autoclean; use myapp::person;  $person = myapp::person->new();  # works. $person->id( myapp::type::field->new() ); $person->id->value( 1 ); $person->id->error( 'not found' );  # fails name object has not yet been defined. $person->name->value( 'dave' ); # can't call method "value" on undefined value @ ...  __package__->meta->make_immutable; 1; 

this works, in myapp::test able directly access value , error attributes of person's name , id without first having instantiate new myapp::type::field object each of person's attributes.

or, put way, i'd prefer if user of person class did not have this: $person->id( myapp::type::field->new() ); before being able use id attribute.

is there nice clean way can achieve this?

couldn’t supply default properties?

has 'id' => (     => 'rw',     isa => 'myapp::type::field',     default => sub { myapp::type::field->new } ); 

…or equivalent in build.