From: Mariano Kamp <mariano.kamp@...>
Date: 2006-12-20T05:47:27+09:00
Subject: class_eval and using a block instead of a String?

Hi,

   given the following contrived example I am wondering how to use a  
block with class_eval instead of using the string like in the code  
below?!

   Any ideas?

Cheers,
Mariano

require 'test/unit'
include Test::Unit::Assertions

class Base
   class << self
     def enhance(*attributes)
       class_eval do
         attr_reader *attributes
       end

       initializer = "def initialize(#{attributes.join(", ")})"
       attributes.each {|a| initializer << "@#{a}=#{a}\n"}
       initializer << "end"

      # ------
      class_eval initializer # <-------
      # ------
     end
   end
end
class Derived < Base; end

Derived.enhance(:a, :b, :c)
d = Derived.new("a", "b", "c")

assert_equal "a", d.a
assert_equal "b", d.b
assert_equal "c", d.c