Timothy S. Nelson wrote:
> On Mon, 23 Feb 2009, Moritz Lenz wrote:
>> Timothy S. Nelson wrote:
>>>     Another question for everyone - is there some way I can extend a class
>>> in such a way that it implements another role?
>> class A does B does C { ... }
>> where B and C are roles.
>>> For example, say I have a
>>> class Class::A that implements role Role::A, and I want it to also implement
>>> Role::B (and I provide an implementation), is there any way I can make it so
>>> that *every* instance of Class::A implements Role::B, while doing this from 
>>> a
>>> module that doesn't contain Role::B?
>> Well, the Role::B must be visible in your scope where you do the
>> composition.
>> Or is your question much more complicated than that, and I am simply to
>> dumb to grasp it?
>       Maybe I'm too dumb to communicate it.  Let me give an example.  Say I 
> do this:
> $file = IO::File.new(...)
>       And I want all IO::File objects anywhere in my program (including ones 
> returned from other libraries) to all be able to .bark().  Can I do something 
> like this?

Ah, that's called monkey patching, and generally considered rather evil.

It might work like this:

class IO::File is also does BarkRole { ... }

But it's not something you want to advertise anywhere.


Moritz Lenz
http://perlgeek.de/ |  http://perl-6.de/ | http://sudokugarden.de/

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