Greetings, wise monks!

After about a year's hiatus, I've recently found an excuse to return to Perl, and decided to finally take Moose out for a spin. After years of using AUTOLOAD to generate accessors/mutators, I feel like I've been (poorly) reinventing wheels when better alternatives were right there on CPAN. Well, no matter...

Probably because I've spent too much time programming in Java, I get this urge to declare abstract methods. I realize the benefit isn't there when using Perl as opposed to a statically typed/compiled OO language such as Java, but I like to clearly point out methods I expect subclasses to implement. So right now, I've written something like: 

package AbstractWidget;

use Moose;
use Carp;

sub get_widget_type{
    confess(qq["get_widget_type" must be implemented by a subclass!]);
}

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Now if I forget to implement get_widget_type in my SnazzyWidget class, I get a helpful error message with a stack trace instead of the rather cryptic and confusing "Can't locate object method "get_widget_type" via package "SnazzyWidget"".

I half expected to find a Moose extension that would allow me to express this more concisely, providing a method like 

has_abstract 'get_widget_type'

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or 
expects 'get_widget_type'

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I've done some searching on both PerlMonks and CPAN to no avail. Is my interest in abstract methods misplaced? Or is there some other pattern Moose'ers employ that has a similar effect? Any input you have for me is much appreciated!

I had a suspicion that Moose Roles might lead me to a satisfactory solution, but apparently others have had the same idea... and the manual is quite clear about this:

If you are familiar with the concept of abstract base classes in other languages, you may be tempted to use roles in the same way.
You can define an "interface-only" role, one that contains just a list of required methods.
However, any class which consumes this role must implement all of the required methods, either directly or through inheritance from a parent. You cannot delay the method requirement check so that they can be implemented by future subclasses.

In reply to Abstract Methods in Moose by crashtest

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