From: dblack@...
Date: 2007-08-16T01:13:50+09:00
Subject: Re: Singleton or full static class

Hi --

On Thu, 16 Aug 2007, Frank Meyer wrote:

> In other languages I'm using the singleton pattern when I need a
> globally accessible object. But in Ruby so much is an object or behaces
> like an object (or can be treated as an object) I'm not sure if I should
> use the singleton pattern or make all methods to class methods and use
> class variables.
> What is the best practise in ruby?

There's no one answer to that (except I tend to frown on class
variables, because they're so unencapsulated and weird :-)  You can
create a class, or for that matter any other constant, which will be
visible from "below":

   C = Object.new
   def C.greet
     puts "hi"
   end

   class D
     def initialize
       C.greet
     end
   end

   D.new       # hi

and so on. Or C can be a class or a module. There are lots of
different techniques available; I don't think there's one that's
always better than all the others.


David

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