From: Florian Frank <flori@...>
Date: 2005-05-07T06:54:27+09:00
Subject: Re: RCR 303: nil should accept missing methods and return nil

John Carter wrote:

> A very simple and generic way of improving the reliability of Ruby
> programs is to implement the NullObject pattern by allowing nil to
> accept all and every method instead of throwing a NoMethodError.

Great! I've so long waited for something like this. I have just written
a very reliable program, with this new feature:

class NilClass
  def method_missing(*ignore) nil end
end

class Counter
  def initialize
    @count = 1
  end

  attr_reader :count

  def increase
    @count += 1
  end
end

class DoSomething
  def initialize
    @coutner = Counter.new
  end

  def count_done
    @counter.count
  end

  def do_it
    @counter.increase
  end
end

ds = DoSomething.new
10.times do
  ds.do_it
end
puts "Have done it #{ds.count_done} times."

-- 
Florian Frank