From: ara.t.howard@...
Date: 2006-07-13T00:07:42+09:00
Subject: Re: prototype design pattern

On Wed, 12 Jul 2006, Berger, Daniel wrote:

> Hm, it's not at
> http://wiki.rubygarden.org/Ruby/page/show/ExampleDesignPatternsInRuby

http://en.wikipedia.org/wiki/Prototype-based_programming

> Anyway, it looks to me like some combination of .clone plus a factory.  I'm
> not sure there's any real savings in Ruby to doing things this way, but I'd
> be happy to be proved wrong.

hi daniel-

savings is only keystrokes.  but it can very elegant looking and, these days,
ruby coding bores me unless it looks good too - solving problems is just too
easy in it to provide enough challenge!  ;-)  take this code for example:

     fortytwo :~/eg/ruby/prototype > cat a.rb
     require 'prototype'

     singleton = Prototype.new{
       @a, @b = 40, 2

       def answer() @a + @b end
     }

     p singleton.answer

     fortytwo :~/eg/ruby/prototype > ruby a.rb
     42



     fortytwo :~/eg/ruby/prototype > cat b.rb
     require 'prototype'

     DB = Prototype.new{
       host 'localhost'
       port 4242

       def connect() 'do something' end

       def inspect() [host, port].join ':' end
     }

     p DB
     p DB.host
     p DB.port

     fortytwo :~/eg/ruby/prototype > ruby b.rb
     localhost:4242
     "localhost"
     4242


do you like the look of it?

i'll post my impl in a follow-up.

cheers.


-a
-- 
suffering increases your inner strength.  also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama