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in reply to Re: Solving compositional problems with Perl 6 roles
in thread Solving compositional problems with Perl 6 roles

Well, it depends. If you are using roles, there are a couple of ways of resolving conflicts, but basically it works out as:

class Elf is Character does Thief does Scout { method hide { .Scout::hide(@_) } ... }

However, if you prefer, you can have your cake and eat it too.

method hide ($self: $action) { # $self is required here because the topicalizer assigns # $action to $_ given $action { when Skulking { $self.Thief::hide($action) } when Stalking { $self.Scount::hide($action) } } }

And that's nice because theoretically, if your elf knows various professions, she should know how the activities with those professions vary, just as one person might know how to drive a race car but wouldn't think of doing that with a dump truck, even though both activies are driving.

Unfortunately, when it comes to your specific example with mixins, I'm a little less clear about disambiguation. When you use a role at runtime on an instance, you get new anonymous classes that are related to the instance via inheritance. Thus, the following has the inheritance ordering problem again:

$elf does Thief does Sentry;

In that example, $elf.hide calls Sentry.hide as Thief.hide is further up the inheritance tree. This seems to limit the utility of mixins, but I can't be sure. Further clarification would be nice.

Cheers,
Ovid

New address of my CGI Course.