From: James Moore <banshee@...>
Date: 2006-12-17T16:35:59+09:00
Subject: Re: method_missing question

> So anyway, here's a starting point.  The trick is to use instance_eval
> to change the value of 'self' within the block.
> 

More straightforward to grab the block, make it a method of the current
object, then call that method?

require 'pp'

class ReadableThing
  def book &block
    ugly_call_to_get_the_eigenclass = class << self; self; end
    ugly_call_to_get_the_eigenclass.send :define_method, :___secret_method,
block
    send :___secret_method
  end
  
  def title
    pp 'a title'
  end
end

r = ReadableThing.new

r.book do 
  puts "self is: #{self.inspect}\n"
  title
end

C:\rx\rv\bin>ruby r.rb
self is: #<ReadableThing:0x28e40fc>
"a title"

It does leave a reference to the block lying around - you'd probably want to
clean that up for production code.

 -- James Moore