Is there a way to create temporary namespaces and constants in Ruby?

Question

I have a class:

class MyClass
  def self.say_hello
    puts "hello"
  end
end

and I want to create a process to override the class and its method temporarily:

begin "a temporary namespace, constants, variables and methods within this code"
  Thread.current[:neverland] = -> do
    Object.instance_exec do
      class MyClass
        def self.say_hi
          puts "hi"
        end
      end

      MyClass.say_hi
      MyClass.say_hello
    end
  end
end

> Thread.current[:neverland].call
=> "hi"
=> "hello"

> MyClass.methods - Object.methods
=> ["say_hello"]

> MyClass.say_hi
=> undefined method `say_hi' for MyClass:Class (NoMethodError)

Is there something like this in Ruby or am I just dreaming? Namespace pollution-free, temporary constants, methods, namespace, class. Clean, focused and optimized code, without too much distractions.

Answer 1

You're probably thinking of something like Refinements that are scheduled for release in Ruby 2.0.

Until then you're going to have to be creative.