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