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Re^4: Moose "unions" and inheritance

by PetaMem (Priest)
on Nov 30, 2012 at 13:49 UTC ( #1006477=note: print w/replies, xml ) Need Help??

in reply to Re^3: Moose "unions" and inheritance
in thread Moose "unions" and inheritance

Moose type constraints are not strings, they are instances of Moose::Meta::TypeConstraint.
Sure, I assumed they have semantics beyond 'being a String'. I just meant from the syntactic perspective, Moose::Manual::Types pretty much makes it look like the types are strings. At least
... isa => Str | ArrayRef, ...

doesn't work without MooseX::Types (Bareword "Str" not allowed while "strict subs"...)

Anyway, I tried to make this inherited union constraints "do what I mean" for multiple inheritance and came up with
package ValAtom; use strict; use warnings; use 5.10.1; use Moose; use MooseX::Types::Moose -all; extends 'KeyAtom', 'JustTesting'; has '+data' => ( isa => __PACKAGE__->_existing_constraint('data') . ' | ArrayRe +f | HashRef', ); sub _existing_constraint { my ($class, $attr) = @_; return join ' | ', map { $_->meta->find_attribute_by_name($attr)->type_constraint } $class->meta->superclasses; } 1;
Back to string again - obviously - as I couldn't figure out how to do it otherwise. But this seems to work.

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