From: Trans <transfire@...>
Date: 2007-10-16T00:23:43+09:00
Subject: Re: RubyTraits 0.1



On Oct 15, 8:11 am, Yukihiro Matsumoto <m...@ruby-lang.org> wrote:
> Hi,
>
> In message "Re: RubyTraits 0.1"
>     on Mon, 15 Oct 2007 23:39:24 +0900, Trans <transf...@gmail.com> writes:
>
> |> Even though I like the concept of traits, traits and modules are too
> |> close in concept, too different in behavior.  Having both in a
> |> language may cause confusion.  Too bad I didn't know about traits when
> |> I designed Ruby.
> |
> |What behavior difference are you thinking about? To the end-programmer
> |wouldn't it look mostly the same?
>
> Yes, that's why I said "too close" to have them both.
>
> The biggest difference I concern is traits inject attributes where
> modules create relationship.  Modules can conflict (overriding rule
> applied), traits can't.
>
> If I knew traits before designing Ruby, I'd have chosen traits over
> modules.  But that's the life.

I see. So you don't really like the fact that modules fit into the
inheritance chain? That's interesting. The traits lib I wrote for
Facets actually uses the inheritance. Eg:

class Module

  def +( other )
    mod1 = other.clone
    mod2 = clone
    mod1.module_eval{ include mod2 }
    return mod1
  end

So instead of injection there's relationship, but in every other
respect its like traits. Is that not a good Ruby-esque way to do
traits? Maybe even better than injection actually?

T.