From: Simon Strandgaard <neoneye@...>
Date: 2004-03-23T04:34:39+09:00
Subject: Re: forwardable.rb

On Tue, 23 Mar 2004 02:15:18 +0900, Dave Thomas wrote:
> I'm being dense today, but can anyone think of a real-world application 
> of SingleForwardable? I keep trying to come up with examples, but I 
> haven't yet discovered any that aren't better written as methods inside 
> the class itself.
> 

The only usage I can think of is unittesting. Imagine that the Values
class is some class that we didn't wrote and that we somehow needs to
populate it with data.


server> ruby a.rb
#<Values:0x810a5e4 @values=[1, 2]>
server> expand -t2 a.rb 
class Values
  def initialize
    @values = []
  end
  attr_reader :values 
end

# imagine that this is a testcase, located in a
# different file.
require 'forwardable'
v = Values.new
v.extend SingleForwardable
v.def_delegator("@values", :<<, "append")
v.append(1)
v.append(2)
p v
server>


I don't know if this can be useful.. some kind of mockobject is probably
better to use in this case.

--
Simon Strandgaard