From: Trans <transfire@...>
Date: 2007-09-01T07:10:37+09:00
Subject: Re: python-style decorators



On Aug 31, 12:47 pm, "Robert Dober" <robert.do...@gmail.com> wrote:

> Still trying to get the problem
> I know that you know (do I?) that you can do
> module M
>   def foo; "foo" end
> end
> class X
>    extend M
> end
>
> where's the catch?

When you want class-level methods that go along with your instance
methods.

  module M
    def self.foo
      @foo ||= {}
    end
    def foo
      self.class.foo
    end
  end

  Class X
    include M
  end

  X.new.foo  #=> ERROR

If one could include singletons, the solution would be as simple as:

  class X
    extend(class << Foo; self; end)
  end

But as things are you need some sort of "trick".

T.