From: "Berger, Daniel" <Daniel.Berger@...>
Date: 2005-05-18T03:38:33+09:00
Subject: Re: Forwardable, reworked

> -----Original Message-----
> From: Eric Hodel [mailto:drbrain@segment7.net] 
> Sent: Tuesday, May 17, 2005 11:05 AM
> To: ruby-core@ruby-lang.org
> Subject: Re: Forwardable, reworked
> 
> 
> On 17 May 2005, at 04:36, Daniel Berger wrote:
> 
> > --- Robert McGovern <robert.mcgovern@gmail.com> wrote:
> >
> >>> class Foo
> >>>    extend Forwardable
> >>>
> >>>    delegate :to_i => :@number
> >>>    delegate [:to_s, :reverse] => :@string
> >>>
> >>>    def initialize
> >>>      @number = 5
> >>>      @string = "foobar"
> >>>    end
> >>> end
> >
> > This should do the trick:
> >
> > def delegate(hash)
> >    hash.each{ |methods, accessor|
> >       methods = methods.to_s if methods.kind_of?(Symbol)
> >       methods.each{ |method|
> >          def_instance_delegator(accessor, method)
> >       }
> >    }
> > end
> 
> I think I would rather see:
> 
> delegate :@number, :to_i
> delegate :@string, :to_s, :reverse
> 
> def delegate(ivar, *methods)
>    methods.each { |method| def_instance_delegator ivar, method } end

It's six one way and half a dozen the other.  Both look good to me,
though the officially submitted patch uses the reversed, hash style that
Florian originally suggested.  If you feel strongly about it, please
post a response to Patch 1923 on RubyForge.  Matz and/or Tanaka may
agree with you.

> The kind_of? feels so clumsy.  (And I forgot how String#each worked  
> since I never use it.)

Actually, I replaced that line in the submitted patch with:

methods = methods.to_s unless methods.respond_to?(:each).  Just a wee
bit of duck typing to keep things sane.

Regards,

Dan