From: Jim Weirich <jim@...>
Date: 2006-03-23T22:23:41+09:00
Subject: Re: Is this a kind of design patterns?

Robert Klemme wrote:
> IMHO this is not thread safe.  If you need the method interface, you
> could do something like
[...]
> :-)

I did catch the smiley.  :)

Given that the original returned a new object on every invocation, a 
race condition that might generate an extra light weight object or two 
at initialization seems to be a low risk.

However, if I were really concerned about the race condition, I think I 
would go the metaprogramming route rather then the dynamic lookup route. 
Something more like this:

  class Color
    ...
    class << self
      private
      def define(name, color)
        class_eval "#{name.to_s.upcase} = color"
        class_eval "def Color.#{name}; #{name.to_s.upcase}; end"
      end
    end

    define :red, Color.new(255, 0, 0)
    ...
  end

;)

--
-- Jim Weirich

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