From: matz@... (Yukihiro Matsumoto)
Date: 2000-09-12T13:37:54+09:00
Subject: [ruby-talk:4884] Re: Re-binding a block

Hi,

In message "[ruby-talk:4883] Re-binding a block"
    on 00/09/12, Dave Thomas <Dave@thomases.com> writes:

|     class Dave
|       @@block = proc { puts @name }
|       @name = "class level"
|       def initialize
|         @name = "instance level"
|       end
|
|       def block
|         @@block.call
|       end
|     end
|
|     Dave.new.block
|
|It will always output "class level" as @name is bound at the time the
|block is created. Is there any way to change that binding at runtime
|so that I can call the block and have it output "instance level"?

Here's the trick.  Don't tell anybody. ;-)

     class Matz
       @@block = proc { puts @name }
       @name = "class level"
       def initialize
         @name = "instance level"
       end

       def block
         self.instance_eval(&@@block)
       end
     end

     Matz.new.block

							matz.