Working through an old @why post on metaprogramming

since I'd like to make the JRuby rabbitmq stuff a bit less boilerplate.

why/metaid/attr_abort.rb

@@ -0,0 +1,9 @@
+class Class
+  def attr_abort(*args)
+    abort "Please no more attributes today."
+  end
+end
+
+class MyNewClass
+  attr_abort :id, :diagram, :telegram
+end

why/metaid/happy_truck.rb

@@ -0,0 +1,5 @@
+require_relative 'mail_truck'
+
+class HappyTruck < MailTruck
+  company "Happy's -- We Bring the Mail, and That's It!"
+end

why/metaid/mail_truck.rb

@@ -0,0 +1,15 @@
+require_relative 'metaid'
+
+class MailTruck
+  attr_accessor :driver, :route
+
+  def initialize(driver, route)
+    @driver, @route = driver, route
+  end
+
+  def self.company(name)
+    meta_def :company do
+      name
+    end
+  end
+end

why/metaid/metaid.rb

@@ -0,0 +1,19 @@
+class Object
+  def metaclass
+    class << self
+      self
+    end
+  end
+
+  def meta_eval(&block)
+    metaclass.instance_eval(&block)
+  end
+
+  def meta_def(name, &block)
+    meta_eval { define_method(name, &block) }
+  end
+
+  def class_def(name, &block)
+    class_eval { define_method(name, &block) }
+  end
+end