From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2005-07-19T08:45:39+09:00
Subject: Re: How to find out a method's defining class ?

On Tue, 19 Jul 2005, Rolf Gebauer wrote:

> Hi,
>
> 1. a method created with Classname.method( 'method_name' )
> knows the class it's defined for, as inspect shows.
>
> Object.methods returns an Array of Strings only.
>
> ObjectSpace.each_object( Method ) delivers methods created
> as in 1. only
>
> Does Reflection provides a way to find out ?
>
> Thanks in advance

i don't know a direct way, but maybe:

   harp:~ > cat a.rb
   class Object
     def defines method
       singleton_class = class << self; self; end
       ([singleton_class] + self.class.ancestors).reverse.each do |a|
         return a if a.instance_methods.include? method
       end
       return nil
     end
     alias defines? defines
   end


   module M
     def foobar; end
   end
   class C
     def foo; end
   end
   class B < C
     include M
     def bar; end
   end

   obj = B::new
   p(obj.defines('foo'))
   p(obj.defines('bar'))
   p(obj.defines('foobar'))

   a = []
   class << a
     def singleton_method; end
   end
   p(a.defines('each'))
   p(a.defines('singleton_method'))
   p(a.defines('not_defined'))


   harp:~ > ruby a.rb
   C
   B
   M
   Array
   #<Class:#<Array:0xb75d1db4>>
   nil


note that this is just an idea - but it may suit your purposes.

hth.


-a
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