From: Robert Klemme <shortcutter@...>
Date: 2007-11-08T22:08:24+09:00
Subject: Re: alternate to case; generating a list of sub-classes

2007/11/8, Thufir <hawat.thufir@gmail.com>:
> The below uses pseudo-random number generation to populate an array
> with various monsters, all inherit from Creature.  Can a list of
> classes which inherit from Creature be generated automagically?  There
> must be a better technique to fill the array then the case
> statement...

I usually do this when I want to also recursively track subclasses:

module Hierarchy
  def inherited(cl)
    superclass.instance_eval { inherited cl }
    (@children ||= []) << cl
    cl.extend Hierarchy
  end

  attr_reader :children
end

class Foo
  extend Hierarchy
end

class Bar < Foo
end

class Dice < Bar
end

p Bar.children
p Foo.children

Cheers

robert

-- 
use.inject do |as, often| as.you_can - without end