From: "ara.t.howard" <ara.t.howard@...>
Date: 2008-08-21T23:50:10+09:00
Subject: Re: Find all subclasses of a class/module


On Aug 21, 2008, at 7:55 AM, James Coglan wrote:

> Hi list,
>
> I'm trying to find all the classes/modules that descend from a  
> particular
> class/module. Please tell me there's a better way than this:
>
> http://gist.github.com/6560
>
> -- 
> James Coglan

just let ruby track it for you:

cfp:~ > cat a.rb
class A
end

class B < A
end

class C < A
end

class D < B
end

p D => D.subclasses
p C => C.subclasses
p B => B.subclasses
p A => A.subclasses
p Object => Object.subclasses



BEGIN {
   class Class
     def inherited other
       super if defined? super
     ensure
       ( @subclasses ||= [] ).push(other).uniq!
     end

     def subclasses
       @subclasses ||= []
       @subclasses.inject( [] ) do |list, subclass|
         list.push(subclass, *subclass.subclasses)
       end
     end
   end
}




cfp:~ > ruby a.rb
{D=>[]}
{C=>[]}
{B=>[D]}
{A=>[B, D, C]}
{Object=>[A, B, D, C]}


a @ http://codeforpeople.com/
--
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better. simply reflect on that.
h.h. the 14th dalai lama