----- Original Message ----
> From: Stevan Little <[email protected]>
>
> I am also very much not a fan of adding features to solve problems that are
> easily solved in other ways. Moose already has a fairly large feature set and
> I
> am pretty adverse to adding more unless they are first vetted through a
> MooseX::
> module (see the section on NEW FEATURES in Moose::Manual::Contributing).
I don't particularly care for the idea of creating an interface role for every
role which might also serve as an interface because that violates chromatic's
insistence that things be easy lest we discourage people from using roles to
their full power.
That being said, I'll look at the MooseX route. Thanks.
By the way, was this really a bug?
> > #!/usr/bin/env perl
> >
> > package My::Role;
> > use Moose::Role;
> > sub foo { __PACKAGE__ }
> >
> > package Bar;
> > use Moose;
> > with 'My::Role' => { excludes => 'foo' };
> >
> > print Bar->foo;
> > # Can't locate object method "foo" via package "Bar" at role.pl line 13.
That shouldn't be a runtime issue, but a composition time failure. Should I
file a bug report?
Cheers,
Ovid
--
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> - Stevan
>
>
> On Apr 28, 2009, at 3:53 AM, Ovid wrote:
>
> >
> > There are times that you want to use a role, but only as an interface.
> > If 9 out of 10 classes use the implementation, it's annoying to have
> > that 10th class have to do this:
> >
> > with 'My::Role' => { excludes => \...@a_long_list_of_methods };
> >
> > What about something like this?
> >
> > with 'My::Role' => { includes => [] };
> >
> >
> > That
> > would be the mutually exclusive opposite of 'excludes'. No methods
> > would be composed into your class, but they would all be added to the
> > 'requires' list. This (I think) would largely overcome chromatic's
> > objection (http://use.perl.org/comments.pl?sid=42835&cid=68295)
> > that if someone wants to use a role as an interface, being forced to
> > manually exclude every method is annoying and would discourage role
> > use. So a role could be trivially used as an interface, if desired,
> > even if implementation is provided.
> >
> > Plus, if you still needed two of the 8 methods a role provided:
> >
> > with 'My::Role' => { includes => [qw{ foo bar }] };
> >
> > Seems to me that this is the best of both worlds. This would also make it
> trivial to add the "warn on conflict" back in because the entire objection
> seemed to be that the warning coupled with it being annoying to exclude all
> methods would discourage role use (an argument which penalizes the programmer
> who values safety and correctness, but then, Dominus doesn't like how we
> constantly encourage "use strict", either). While I do realize I've lost
> this
> argument, at least adding "includes" would make roles a tad more flexible and
> make some of my work easier if I get around to writing "MooseX::Role::Strict".
> >
> > This
> > also shows what I *think* is a limitation in 'excludes'. All methods
> > listed in a role should be explicitly added to the 'requires' list.
> > The following is a runtime failure:
> >
> > #!/usr/bin/env perl
> >
> > package My::Role;
> > use Moose::Role;
> >
> > sub foo { __PACKAGE__ }
> > package Bar;
> > use Moose;
> > with 'My::Role' => { excludes => 'foo' };
> > print Bar->foo;
> > # Can't locate object method "foo" via package "Bar" at role.pl line 13.
> >
> > Thoughts?
> >
> > Cheers,
> > Ovid
> > --
> > Buy the book - http://www.oreilly.com/catalog/perlhks/
> > Tech blog - http://use.perl.org/~Ovid/journal/
> > Twitter - http://twitter.com/OvidPerl
> > Official Perl 6 Wiki - http://www.perlfoundation.org/perl6
