/lib/meta.rb

 1# A set of methods to help create meta-programming gizmos.
 2class Object
 3  # The metaclass is the singleton behind every object.  
 4  def metaclass
 5    class << self
 6      self
 7    end
 8  end
 9
10  # Evaluates the block in the context of the metaclass
11  def meta_eval &blk
12    metaclass.instance_eval &blk
13  end
14
15  # Acts like an include except it adds the module's methods
16  # to the metaclass so they act like class methods.
17  def meta_include mod
18    meta_eval do
19      include mod
20    end
21  end
22
23  # Adds methods to a metaclass
24  def meta_def name, &blk
25    meta_eval { define_method name, &blk }
26  end
27
28  # Defines an instance method within a class
29  def class_def name, &blk
30    class_eval { define_method name, &blk }
31  end
32end