Moose, arrayref, and does?

einhverfr has asked for the wisdom of the Perl Monks concerning the following question:

Fellow monks

I have a moose class with has an attribute which is an arrayref of objects. I would like to require that each object consumes a specific role but I don't want to require an isa relationship to a specific class.

Consider

package myclass;
use moose;

# this won't work since ElementRole is a role
has parts => (is => 'ro', isa => 'ArrayRef[ElementRole]');

# this won't work since it is an arrayref
has parts => (is => 'ro', does => 'ElementRole');
[download]

Is there a way to do this or should I just revert to an abstract superclass?

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Re: Moose, arrayref, and does? by tobyink (Canon) on Oct 06, 2014 at 13:53 UTC
You could use Types::Standard, where it's fairly easy... `use Types::Standard qw( ArrayRef ConsumerOf ); ..., isa => ArrayRef[ ConsumerOf["SomeRole"] ], ...` [download] Or you can use Moose::Meta::TypeConstraint and Moose::Util::TypeConstraints something like (untested): `isa => find_type_constraint("ArrayRef")->parameterize(role_type "MyRol +e")` [download] toby döt ink	[reply] [d/l] [select]
Re: Moose, arrayref, and does? by McA (Priest) on Oct 06, 2014 at 13:51 UTC
Hi, have a look at `ConsumerOf`. UPDATE: While searching for the right reference, Tobyink posted a more complete and definitively more authorative answer. Therefore, look below. Regards McA	[reply] [d/l]
Re: Moose, arrayref, and does? by tobyink (Canon) on Oct 07, 2014 at 18:53 UTC
Here's another answer... `use MooseX::Types::MoreUtils; isa => "ArrayRef"->$_of({ role => "My::Role" })` [download] toby döt ink	[reply] [d/l]